This is strange, but will check on my receiver tomorrow (it's at the new house, I'm at the old house). The different surround modes do differ significantly in terms of how much energy goes into center vs surrounds vs main (ie they react differently to different content) but I'm pretty sure the actual channel settings don't change. Will let you know...

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8