I wish copilot.vim had a way to insert only a token from the suggestion. I often get stuff which is partly correct but "diverges".
there is a somewhat hacky way to accept just a word, to my understanding, since copilot.vim allows you to access the raw text that's being suggested. try out the snippet in the linked comment:
It’s a similar job, but a different value. Copilot writes code you don’t know yet (supposedly), while this speeds up typing what you know you’d like to type. Both modes could be useful, I think.