I believe dev confirmed a short while back that it’s under development in response to another similar post here.

Do you mean the individual upvotes or downvotes, or the current score of the post? For me I can see the current number of upvotes just fine in the app (top right corner of the comment).

If you want to see the individual upvotes and downvotes, I think this is not possible, but not because of Boost. I think this is a limitation of Lemmy. So in this case you would have to request the feature in the Lemmy development channel :)