macOS digital crossover options

I currently run a digital setup, that is:

old Mac Mini running iTunes->Jack->AULab->Dirac->CrossoverUnit->AuDelay (for time alignment)->Audiofire 12->8 channel amp->4 way OB speakers.

The CrossoverUnit audio unit was generously written by Andrew McPherson and has allowed me to construct a phase coherent crossover using LR2 filters.

Being of a certain age I'm listening to Pink Floyd as I type this and the sound quality is still to my liking. However I've just upgraded the almost obsolete 2006 Mac Mini to a modern M1 based version running Big Sur with the idea of porting my setup - but no joy; the OS has moved on and left the trusty CrossoverUnit and Jack behind. So consequently I am looking to implement a new approach.

I have tried BlackHole->AULab->Multiband frequency splitter (a freebie from Mani Consulting Limited/BlueMangoo via the AppStore). This promises to implement a phase coherent crossover in a single component. However the audio unit will not load in AULab.

I guess I have a preference for an audio unit approach and it looks like FabFilter and BlueCat may supply something that can do the job but with a hike in complexity. Another options may be to use Pure music or JRiver to implement the crossover.

I would therefore appreciate any advice on MacOS based approaches that would allow me to implement a digital crossover and bridge the gap between a digital source and my audio interface.
 
@jccart sorry for the tardy reply! I’ve only just got back into it having shaken my setup considerably, in fact it is still a work in progress. However I have made some progress; my setup is now: an aggregate device of 2 channel black hole and MOTU 8A->AULab->Gaffel splitter->MOTU 8A->8 amps->OB speaker. This seems to work. However having dismantled my home built 8 channel amp, I’m now rebuilding it as 8 mono amps (gloriously silly).