I never cared for splitters, they can get lost... some are flaky and may not work
as for not using an active out of the m1, I always ran 2 digital chains whenever possible just in case... perhaps that was his thinnking as well
this guy could also use one of the aes outs to feed his deck but that would require an pulse transformer like the canare to step the signal down from 110ohm to 75ohm and also to adapt the xlr of the aes down to the coax. this all adds bulk though and having a 2nd coax out would be much easier.