I am 100% sure that @EHG_Mike confirmed a while ago, that any Increased [Insert Item Type] Blessing would not affect how many uniques of that type are dropping.
(I am so sure about that, because I know that there was another discussion/question arising from his statement, that drops in LE don’t work how many people think it works. The game rolls rarity first and then type I think. This also leads to Items like Unique Off-Hand Catalyst and Unique Bows for examples to drop as much as for any other class, that usually has lower drop rates for that type.)
For that statement I could even find one written source, but I am sure Mike explained this on dev stream as well:
But For god sake’s I can’t find where he said that with the blessings though, might be on the dev stream.
I am pretty sure that statement was given multiple times over the last couple of months/year.
But @Trasochi did confirm on discord not so long ago, that it would affect uniques and set items of that type dropping.
But it will not affect the specific drop boss drops at all.
Trasochi is the Lead Developer, but I think most of the people in EHG, at least in the Developer Team do various different Things anyway, because they are still relatively small.