Wanting to do room correction in a Roon based 2.1 system using two endpoint/dac's?

My speakers are a pair of KEF LS50’s and a REL T7/i subwoofer.
I plan to add room correction of some kind and I want to do this
through Roon software. I am just starting to research this topic,
so total newbie.

I am wondering if it is feasible or advisable to run the subwoofer off
of a separate endpoint/dac, rather than its current configuration where it is
driven from the power amp outputs. It seems this might permit much
more accurate control of phase/timing and perhaps makes the EQ
easier and better. Is this possible to do in Roon, in essence using it
as a digital crossover? If so, what reasonably powerful tool or service
would be appropriate for a newbie to obtain the filters needed to
get up and running?

My concept is to use 2 RAAT endpoints to create 2 Roon Zones. One Zone will be for the LS50’s (Satellite Zone) and the other for the subwoofer (Sub Zone). Each Zone would have it’s own DSP, to create the crossover and room correction functionality. The Zones would be grouped to play simultaneously.

Would this work? Can the timing of the simultaneous play of the two zones be close enough for high sound quality?

You could do this technically, but the time sync would have to be identical every time the endpoints reconnect to the core. Otherwise the phase will shift, since it represents the difference in time between two signals at a given frequency.

But the only reason to split the zones is for active crossovers between your speakers. You can do all phase correction on the single zone to get linear phase from the crossover filters in your sub output.