Google's John Mueller said that the size of your header tags, i.e. H1s, H2s, etc, does not matter for SEO or ranking purposes. John said it might matter for users and conversions but for SEO, nope.
John was asked "would google deem huge heading font size as a sign of "overdoing it", thus lower quality?" John said "I can't imagine that it would matter for SEO. Test it with your users instead."
Here are those tweets:
I can't imagine that it would matter for SEO. Test it with your users instead.
— johnmu: nothing is permanent, use 302 always 💫 (@JohnMu) November 2, 2022
So making your header tags larger or smaller won't make a difference for ranking purposes but your users might care (or not).
Forum discussion at Twitter.