I usually try to optimize for CPU usage more than I do for RAM, mostly because I care about my battery life and for things to remain snappy. Although Vicinae does a lot of caching where it can it probably maintains a quite reasonable memory footprint when compared to apps with web frontends.
Extension resizing would be tricky from a UX standpoint, as it would make things a little bit unpredictable, but general window resizing will definitely be a thing
I have a very similar experience, I used mac for a long time, then moved to linux and used the simpler alternatives. Then I found Raycast and their extension system, and thought it would be amazing to have something similar on Linux, so I made this :)