This is one of the better suggestions that I've seen on this sub. More on reddit.com

You almost answered your question (for the most part) in your post. Bing has always and will always be behind google in algorithm based bidding strategies and overall development as a whole when it comes to its advertising platform. A big tell is it’s keyword/search term performance. Especially running broad, you’ll oftentimes find more irrelevant search terms triggering your KWs and more volatility between KWs. Keep an eye on your search queries and scope out possible negatives daily for the first week or two. I would do this before pausing the KW as a whole - it could be some badly matched search terms eating up your budget, and not necessarily the term you want to be targeting. Once you’ve built a good list of negatives, you won’t need to check every day. But definitely will always need to keep a good eye on the queries for bing as well as google, but definitely not as much lol. More on reddit.com

its useless. honestly. I tried serveral time only to realise that I waste a n hour. instead use free searches provided by semrush or use ahref free tools. Semrush free search is very limited but it helped me a lot. More on reddit.com

You'll never get it exact. At one point I tried to look at SEMRush keyword results combined with Keyword planner results combined with category average CPCs and a whole bunch of other things to see if I could get closer estimates. It was a lot of work with very little reward. The reality is you're much better off taking what Keyword planner says, and then throwing a ton of disclaimers on it. Say that this is initial volume estimated by Google and likely to change. The CPC estimates are estimates only and also very likely to change. In Bing's case, note that their search volume estimates always lean very optimistic. Then based on the client's budgets and your rough search volumes, and outline a time when you can get a more accurate number once you have real world data (might be a week, might be a month). That's when you can say "after a month, we will have seen actual search volumes and CPCs and will be able to more accurately project spend/conversions/etc." That's how I've always done it and have never had an issue. More on reddit.com