Nice collection!Welcome to MT.o! Though a bit larger than what most would consider keychain-size, here are a few other options to possibly consider for small but capable pliers:Knipex Cobra XS - Perhaps the smallest serious real tool pliers availableVictorinox 91mm pliers - I feel these are more capable than they sometimes get credit for. One negative is that the smallest current production SAK to include them is the four-layer Deluxe Tinker.
The IDL T5 is brand new, but is too loose to keep on a keychain.
The Swiss+Tech tools are small but feel heavier than they are. The pliers shape makes them basically useless as pliers. I don't carry these.