I’m not going to pretend I know all the technical details (Maybe there is a way they can really up the FPS), but in my experience FPS issues with Tower Unite seem to be more rooted in “incompatibility” rather than poor optimization. There are definitely some rough spots on the whole, but overall it runs fine on my subpar PC. My main question would be if you have integrated graphics, which is what I mean by incompatibility. Tower Unite just won’t run well at all with integrated graphics, even if your PC isn’t that horrible overall.
Maybe there is something they can do, but optimization is tough, and similar to bug fixes, they usually add little optimizations over time, not all at once. A lot of this might be baked into UE4 (Maybe an eventual engine version upgrade would help?), so I wouldn’t expect any major changes anytime soon. One of the major factors in getting a “better” (Still not great) PC, for me, was so I could play Tower Unite. Obviously that isn’t important enough on its own, but just an anecdote from somebody who was in a similar situation.