So I spoke to Bill over at v-leds, who's very nice and tried to help me out ... turns out that 7440 socket/bulb holes are the most inconsistent in the industry, ranging from 16mm to 20mm ... The tritons are on the upper range and the escalade sockets on the lower, so there's no way to make them work. One could hypothetically start sanding down the bulb access hole, but it would need to be sanded so much that there might not be any trim notches left to grab onto the bulb itself, and he advised against this approach. So they're heading back from where they came.
Not sure if the same issue will manifest with NNBS Tahoe or Yukon tails, but a measurement would be advisable before any order is triggered.