Advice for lightweight side sleeper

Hi, new to the mattress underground and pretty new floor mattress shopping! I was verging on analysis paralysis, then tried a purple original in store and loved it. I am very early in the trial period and second guessing my choice. I love the coolness and motion isolation. It is softer than my previous mattress, but my shoulder does not sink in far enough to not roll under me. I like it so far and do think it will soften when broken in. But, I’ve seen concerns about sagging in purples and am considering that if I like but don’t love it, the trial period may be the time to return and find something else. I toss and turn a lot and feel I something quite soft to allow my shoulder to sink in and stay comfortable.

Me: 120 lb 5.5 female side and stomach sleeper, would like to spend more time on my side. Sleep hot and easily awakened by partner moving.
Partner: 200lb 6.2 all which way sleeper who isn’t picky and will go with whatever mattress I choose.

Based on what I saw here, I’m considering nest sparrow in plush on my side and something firmer on his, or nest quail in medium on my side. I’m not considering latex due to motion isolation concerns. Which of these would be best for max sinkage/softness for a lightweight sleeper, not getting hot, and motion isolation? I’m not sure the quail will be soft enough, but I’m not sure the sparrow will meet motion isolation needs. I could probably live with a warmer temp than the purple if I found a cooling topper.
Or since I like the purple and it should soften, should I just stick with something I know I like and not second guess? I can’t try a nest in store anywhere near me unfortunately. Appreciate the advice in advance!