I noticed that I have two repositories on my Tumbleweed system, one called "repo-oss" with base URL http://download.opensuse.org/tumbleweed/repo/oss, the other called "openSUSE:Tumbleweed" with base URL https://download.opensuse.org/repositories/openSUSE:/Tumbleweed/standard/. Both seem to contain the same packages - zypper se --installed-only --from [repo] return the same package list for either.

Can I safely remove e.g. the "openSUSE:Tumbleweed" repository without compromising my system?

For completeness, here is the output of zypper lr -P -pu (you can see a lot of cruft has built up that I'm in the process of cleaning up):

# LANGUAGE=en zypper lr -P -pu
#  | Alias                       | Name                                              | Enabled | GPG Check | Refresh | Priority | URI
---+-----------------------------+---------------------------------------------------+---------+-----------+---------+----------+-----------------------------------------------------------------------------------------------------------
 1 | M17N                        | Multilingualization Project (openSUSE_Tumbleweed) | Yes     | (r ) Yes  | No      |   90     | https://download.opensuse.org/repositories/M17N/openSUSE_Tumbleweed/
13 | packman                     | Packman (Tumbleweed)                              | Yes     | (r ) Yes  | Yes     |   90     | http://ftp.halifax.rwth-aachen.de/packman/suse/openSUSE_Tumbleweed/
20 | sputnik-look-and-feel       | sputnik-look-and-feel                             | Yes     | (r ) Yes  | Yes     |   90     | https://download.opensuse.org/repositories/home:/sputnik:/look-and-feel/openSUSE_Tumbleweed/
 2 | SoftMaker_Office_Repository | SoftMaker Office Repository                       | Yes     | (r ) Yes  | Yes     |   99     | http://shop.softmaker.com/repo/rpm
 3 | brave-browser               | brave-browser                                     | Yes     | (r ) Yes  | Yes     |   99     | https://brave-browser-rpm-release.s3.brave.com/x86_64/
 4 | home_awerson_lukehannan     | home:awerlang:branches:home:lukehannan            | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/home:/awerlang:/branches:/home:/lukehannan/openSUSE_Tumbleweed/
 5 | home_deltafox               | home:deltafox                                     | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/home:/deltafox/openSUSE_Factory/
 6 | home_mguessan_davmail       | home:mguessan:davmail                             | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/home:/mguessan:/davmail/openSUSE_Tumbleweed/
 7 | home_superppl               | home:superppl                                     | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/home:/superppl/openSUSE_Tumbleweed/
 8 | home_trmdi_tw               | home:trmdi:Tumbleweed                             | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/home:/trmdi/openSUSE_Tumbleweed/
 9 | home_wstephenson_kwin       | home:wstephenson:kwin                             | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/home:/wstephenson:/kwin/openSUSE_Tumbleweed/
10 | m17n-fonts                  | m17n-fonts                                        | Yes     | (r ) Yes  | Yes     |   99     | http://download.opensuse.org/repositories/M17N:/fonts/openSUSE_Tumbleweed
11 | microsoft-edge-dev          | microsoft-edge-dev                                | Yes     | (r ) Yes  | Yes     |   99     | https://packages.microsoft.com/yumrepos/edge/
12 | network_im_signal           | signal-TW                                         | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/network:/im:/signal/openSUSE_Tumbleweed/
14 | repo-debug                  | repo-debug                                        | Yes     | (r ) Yes  | Yes     |   99     | http://download.opensuse.org/tumbleweed/repo/debug
15 | repo-non-oss                | repo-non-oss                                      | Yes     | (r ) Yes  | Yes     |   99     | http://download.opensuse.org/tumbleweed/repo/non-oss
16 | repo-oss                    | repo-oss                                          | Yes     | (r ) Yes  | Yes     |   99     | http://download.opensuse.org/tumbleweed/repo/oss
17 | repo-update                 | repo-update                                       | Yes     | (r ) Yes  | Yes     |   99     | http://download.opensuse.org/update/tumbleweed/
18 | skype-stable                | skype (stable)                                    | Yes     | (r ) Yes  | Yes     |   99     | https://repo.skype.com/rpm/stable/
19 | snappy                      | snappy                                            | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/system:/snappy/openSUSE_Tumbleweed
23 | suse-opensuse-tw            | openSUSE:Tumbleweed                               | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/openSUSE:/Tumbleweed/standard/
24 | suse-security               | security                                          | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/security/openSUSE_Tumbleweed/
26 | suse-toolchain-avr          | CrossToolchain:avr                                | Yes     | (r ) Yes  | Yes     |   99     | https://download.opensuse.org/repositories/CrossToolchain:/avr/openSUSE_Tumbleweed/
27 | teams-insiders              | teams-insiders                                    | Yes     | (r ) Yes  | Yes     |   99     | https://packages.microsoft.com/yumrepos/ms-teams
21 | suse-base-system            | Base:System                                       | Yes     | (r ) Yes  | Yes     |  200     | https://download.opensuse.org/repositories/Base:/System/openSUSE_Factory/
22 | suse-games                  | games                                             | Yes     | (r ) Yes  | Yes     |  200     | https://download.opensuse.org/repositories/games/openSUSE_Tumbleweed/
25 | suse-server-monitoring      | server:monitoring                                 | Yes     | (r ) Yes  | Yes     |  200     | https://download.opensuse.org/repositories/server:/monitoring/openSUSE_Tumbleweed/

I've had a problem with my tumbleweed setup, stupidly i used zypper update instead of zypper dup, and this made the famous "the following XX packages will NOT be updated" message.

Since then i added packman-essentials to my repos and used the package "openSUSE-repos-Tumbleweed" to rebuild my repo list from scratch. I enabled chrome, vscode and teamviewer repos since i use those programs and they have their own repos. After running "sudo zypper dup --allow-vendor-change" the message about packages not being updated dissapeared and my system is running stable.

Just want to make sure my repos are set up correctly for tumbleweed, and if I understand correctly, i should always use zypper dup instead of zypper up on tumbleweed?