Its P103 as an alternative to P83 - Mixing the two together seems pretty pointless to me. The P103 overpowers P83’s more subtle physicality at normal doses. Very high doses of P83 might help but by then the disinhibition would be turning to disinclination to do anything.
Cohesion has very little effect not tried any of those others with it - P103 adds its own qualities almost regardless of the rest of the mix - its also very like P83 in that respect. The dose only varies over a smaller range depending on the overtness or status of the mix.
P74 - no. I’ve used P103 in P74 mixes before and it does nothing to moderate the 103. And more generally P103 isn’t the stuff for bonding mixes. Its always done best in ONS/hard-hitting sexuals as its so much more immediate.
P96 is the only one that I think I’ve found works the right way on an unconscious level that might offset it.