the room can only be sorted once you are happy with your system
I suspect this is just about 100% the wrong way to approach things. Every system will interact with the room but changing the system to address room interactions, rather than address them at source is a recipe for disaster. For example you may have a mid bass room mode bump so you could look for some speakers with a suck out in that area but why would adding obviously colored speakers help anything? Likewise at the other frequency extreme you could have a lot of reflecting surfaces and find too much treble so seek laid back speakers, it could work but two wrongs don’t make a right.
In other words if you think your system sounds good in an untreated room and then begin to treat the room and it sounds worse it may be that you are now uncovering the colorations that had before been compensating for room interactions. If we (as I believe we should) want a system that is less colored, and more true to the original recording, then the treated room is more accurate, even if your system now sounds worse. Obviously gross mismatches (typically speakers too large for the room with too much bass that cannot be controlled) may be the exception.
The good news is that working on the room will make your system sound more honest. My advice is to take the time to understand how your system interacts with the room, address basic room issues (first reflection points and so on) and then spend time further optimizing how your system then works the room. A well treated room will reveal everything your system is capable of, for better or worse