In retrospect this was a pretty poorly framed point of mine. The point about addition being harder than stated because BPEs break at arbitrary points doesn't make much sense given the previous comment of mine pointed out that GPT-3 can only do addition with comma separators, that mostly (if not quite entirely) defeat that problem. GPT-3 does have to still know the various constructions and additions of 3-digit spans, but that's within its capabilities.