So his opinions kind of did change over that time period, but only from "I reject these words" to "alright, if you insist, I'll try to salvage these words". I'm not sure which policy's best. The second risks arguments with people who don't know your definitions. They will pass through two phases, the first is where the two of you legitimately think you're talking about the same thing but the other is a total idiot who doesn't know what it's like. The second phase is perhaps justifiable umbrage on their discovering that you are using a definition you totally just made up, and how were they even supposed to know.

The former position, however, requires us to leave behind what we already sort of kind of suspect about these maybe-not-actual concepts and depart into untilled, unpopulated lands, with a significant risk of wheel-reinvention.