I think finding a base that would accommodate this would be difficult also. Maybe just a normal mattress and partner uses a wedge pillow to elevate their head? More on reddit.com

Rolling together in a queen is most often caused by the bedframe and second most often caused by the foundation. It is actually rarely the mattresses fault. Maybe you’ve already done this, but before you spend a lot of money on a new bed, have you insured that your bedframe has legs in the center to support it, and you have a strong foundation under the mattress? The best way to check. This is have one if you lay on the floor looking under the bed at the foundation. Then have the second person get in the bed and move around if you see the bottom of that foundation sagging down or flexing at all, you know you have a problem with your frame. More on reddit.com

Trust me, skip the all-in-one sets. Here's what works: Platform base & headboard: Look for a split king platform base online (Amazon has tons). This is the moneymaker - hides your adjustable base and adds storage! Headboard only (optional): If storage isn't a must, a headboard can still look sharp. Avoid two twin XL beds - looks janky and creates a gap. Measure your space before buying! I hope this helps. More on reddit.com

Bought a split Cali king this summer with a L&P adjustable base. Highly recommended for sleeping. Can't be beat. Terrible for everything other than sleeping. Tile floors. I failed to fully appreciate an adjustable split king is literally two separate beds pushed up against each other and nothing anchors the two together. Mind the gap. Def a no-go if you're a frequent spooner. You might have better luck on carpet or a traditional frame. Even on a traditional frame, though, the gap between the two mattresses won't meet perfectly and seal. It will always be there like the cushions on a couch. Good luck! More on reddit.com