Nice set up! Since you are planning to replace the screen, havr you thought of moving both the screen and the projector farther up? (You may have to relocate the fan though...)
I plan on the ultra short throw with the projector behind the center channel. Some of the units (and there aren't tons) are a bit deeper than I'd like but I don't use the main system for video tons (have a bunch of secondary systems, including a projector in the bedroom and plan on swapping the main system projector pictured above) but some also have soundbars so that if I watch something I don't need to use the speakers (don't mind moving the center channel, which weighs 61 pounds, when I want to use it and even making a temporary stand for the front of it to rest on if need be). So that is why I am watching things like the vertical offset and then can see how high I would have to mount a new screen. I had the (Odyssey Audio) custom rack made so I could mount the screen at its current height. My old (Salamander Synergy) furniture is in a spare system now the the 40 inch towers (with a connecting bridge) are just a bit high to my liking (I used it it my old house and had the screen mounted above it). I may have to mount a new screen a few inches higher vs. where it is now, depending on the projector I get. Projectors, of course, have throw distances one can place them and one must use those to figure out where a particular projector can be mounted. Some, like both the ones I have in the main and bedroom system (pic below) have horizontal and vertical lens shift (current ultra short throw projectors I've seen do not).
If it is not too much of pain to move the front height channels a bit (might be), I'll do that as well (could be a drop higher anyway). Right now, I probably can get a 110 inch ALR screen between the height channels and if I can move them a couple of inches, I can do a 120 inch screen (I can live with either. I look at stuff like -
https://www.projectorcentral.com/LG-HU85LA-projection-calculator-pro.htm to see about things like vertical offset, throw distance, etc. The mount in the main system is better and move flexible/adjustable vs. what I have in the bedroom system now so that would work out well rotating the projector in there (below is a pic of the bedroom screen down). Right now just in the preliminary planning stages. I just bought (today) two more comfortable recliners than the ones shown in the picture above and will be moving what I have to another spare system (need to take apart the AV furniture and move it and the components and paint the spare room but it will be about 8 weeks before the new recliners come so I have time). I've had the current screen in the main system in my old house, as well as the current house, for probably over 15 years.