Not really sure what qualifies as underrated/overrated,.. BUT in terms of things I can find on YouTube and general sense of amount of discussion I've seen,.. I think the OPs get more attention than the EDs of these series when I've tended to like the EDs better

Seisenshi Dunbine's ED because power ballads are fun

Gundam IBO S1's ED feels James Bondy with the swung feel and the strings (incidentally Aria the Origination's OP Spirale, also great, kinda feels James Bondy to me but more for the chromaticism,.. ANYWAYS)

and yeah, this was a stacked season (with competition like Bocchi the Rock) but I think my favorite ED of that season was Do It Yourself's ED because of its ultimate comf (kinda gives me the same feel as Nichijou's first ED)