If you're open to upgrading on the video side, one option would be to combine the Epson TW9400 with a HD Fury device to emulate dynamic tone mapping( that is currently natively available only on the JVC PJ's): https://www.avsforum.com/threads/do...hdr10-conversion-w-dtm-on-projectors.3097934/
Might have to stretch your 2L budget slightly, but this (4K + dynamically tone mapped HDR) will be a serious upgrade on the 1080 P Benq, IMO.
Not very keen on upgrading the project for some time since its out secondary source for regular watching and also the PQ seems good enough. Will certainly keep your suggestion in mind whenever i think of a projector upgrade.
I got a Denon X4500H today as many of you suggested to start of with (3600H was out of stock and 4500H was supposed to be having similar setup as the higher line 6500H and so forth). Still boxed as a part of precaution. Wanted to check if 18 AWG wires are ok for rear Atmos speakers since i will need route it all the way across the room from the top and 14/16AWG wires might not look great to begin with and also i dont have a wire of that length at the moment.