How about this idea.
Suppose the firing order is 13726548, that is, on the passenger side bank 13-2--4-. Suppose one is trying to solve the 90-degree exhaust blowdown interference problem at high rpms. The problem is that #3 blows into #1 during its overlap. Adam Christian's Coyote idea was to get #1 and #3 pulses as much on top of each other as possible, such that we only get pumping losses but not cylinder evacuation problem in cylinder #1. So it's desirable to delay the blowdown of #1 and advance blowdown of #3 to get them on top of each other as much as possible.
Make the black path from #3 to exit a large diameter "expressway". This way, hopefully #3's blowdown gets done early. Make the red path from #1 a small diameter "cowpath". This will hopefully delay the blowdown of #1 and keep the dynamic pressure facing the exit high so it'll fight hard the pulse from #3. Advance and shorten the blowdown of #3 and retard and lengthen the blowdown of #1, and hopefully you get the pulses and flow more on top of each other and save the overlap of #1.