I do like the idea of both likes and boosts adding to the score (but not double) which I think (I used translataion) the last comment in the codeberg issue is making.
And even at the risk of making things more complicated I wonder if it would make sense to have separate logic for threads and replies. I think for threads, upvoting to increase relevance/have it be shown to more people in the community makes way more sense, while within the conversation, I feel it correlates much more strongly to simpe approval/disapproval. And if you already are IN the thread thread, you probably want to see upvoted comments, but if you aren't, getting random comments from random convos boosted into your timeline is just confusing.
So I think there's some arguments for separating thread/comment logic, which also opens up new avenues for UI.
Main threads could even get rid of the upvotes/downvote buttons and have one single button "increase reach" button that corelates with fedi-boosting and also is used as the scoring mechanism.
Replies could have the classic up and downvotes with the upvote correlating to likes.
And I guess both main threads and replies could have a separate smaller button that correlates to likes for main threads and boosts for replies.