Dual-Use Subwoofer?

Not quite sure where to put this question - hope it’s in the right place.

My HT and audio systems are separate because my ’good’ stuff is reasonably good, my ’ordinary’ stuff is pretty ordinary, and I don’t want to ’taint’ the good stuff with ordinary stuff.

HT ’boxed’ system:
HK AVR254
Infinity surrounds & sub (sub fed by LFE from the AVR)

Audio:
Krell KRC-3
Bryston 4B-ST
Martin Logan reQuest
Polk PSW650 (signal fed by the preamp)

Because I live in a space-constrained home and want to give the ML’s the ’breathing room’ they really need, I’m wondering if it might be possible to ’consolidate’ by using only one Sub. The Polk unit is the more musical, definitely more than adequate for HT, has both LFE and Left/Right analog inputs, therefore would be the obvious choice.

Do you guys think it would be possible - or at worst, risky - to use the LFE input from the AVR and use the L/R analog inputs from my preamp for the higher-end stuff? I just don’t know my ass from a hole in the ground about electronics and don’t want to risk burning anything out in either the sub, the receiver or the preamp.

Thanks in advance!