Regarding minimizing floors and ceiling reflections.
Hm, I'm wondering when I see your room. Have you tried line speakers that go from floor to ceiling? All speaker elements close together and tight (as tight as possible) to the floor and ceiling? You do not seem to have that high up to your ceiling when the floor-standing speakers are standing right now so line speakers would not be that big.
Something like the one in the attached picture (although tweeters may need to be added to them, ...maybe ..). And then from floor to ceiling.
(not mine in the picture).
But it should be tailored and it is probably DIY that applies and it takes time. Then you would have to re-prioritize your time. Hm ...
Just a thought. Always fun to try new solutions.