Sounds interesting. I should read the paper first, but just going of the text you provided I am unsure how you are relating it to bpe. They are going from vector representations to pseudo-language. Bpe allows tekst to be encoded as a sequence of integers where the integers then are used to lookup the vector representation. So the other way around basically. But maybe you are thinking about reversing the principle?

It is something I have been thinking about and I tried to get some discussion started in another post. Not much response as of yet unfortunately.
I was thinking a scheme where the tokeniser doesn't just give a sequence of tokens but also a set of modifiers to the tokens. The integer we would use as normal to lookup the token embedding, but the modifiers we map onto synthetic (non-trained) dimensions of the token embedding.

The tokeniser would have to be very different from just doing bpe. Instead we would make an attempt of building a tokeniser using a-priori knowledge of different languages. Just as an example:

" bus", "Bus", "busses" for instance would all map to the same integer and the synthetic dimensions would provide the information of the specific variation. Maybe language could be a modifier too. So that the same word in different languages also have the same integer.