Good to hear you are making some progress and getting better results
I like a 350ms RT60 cut off for the tightest bass , non MRC but it depends , some folk like more. It's a suck it and see type proposition.

Try fine tuning your seated position , a lot more effective than moving speakers , easier too , what with 8000's smile

Roon/Tidal, SBT, Trinnov ST2 , Twin Devialet D premiers, Vivid Audio Giya G1 Spirits, dedicated and treated room.
Meridian gear: 568.2mm and DSP5000's acting as TV speakers.