Peter, I'm a FIR noob for sure, but I came to the same conclusion...ie daisy chaining would only make for needless extra latency (unless maybe you're just plain short of taps)
One chaining strategy I am pursuing though, is using FIR in front of IIR crossovers, a channel of FIR for each IIR channel per driver.
I'm using miniDSP and so far haven't experienced any glitches....but I'm thinking it would be a whole lot safer and wiser to use the IIR crossovers in the amps (PLDs), (along with the amps limiters, and probably physical delay too.)
So, I'm putting all phase correction for the IIR crossovers, along with phase and magnitude correction for the drivers, into the miniDSP,......... and leaving essential x-over protection in the amp.
Watch the amp fail first haha
