Any special break in advise George???
Sorry, I was busy chopping up stuff for my Possums for tonight's dinner.
Tricky area, Tri-amping.
Because of the increased dynamics, peak limiting with a hard knee threshold is pretty well essential. [preferably on each amp.]
But, to get it right, you need to monitor voltage outputs and set way before clipping.
Unfortunately, you need to know the voltage limits of the voice coils. You need to blow a few to know where that is.
Generally, run it to full volume then back it off 10% and set your limiter's led at that point.
If you want more, then you have to start doubling the components.