I think it’s best to move upvote/downvote buttons for the comments to the bottom of each comment as regular Lemmy UI, since there is a large amount of dead space on the left side of the comments being taken up by the vote buttons that it’s difficult to read past a few level of nesting.
Plus, regular Lemmy UI layout also shows the exact number of upvotes and downvotes for each comment at a quick glance, which I think is an important aspect of Lemmy.