I've only seen a few Ultraman series, but they tend to do at least one episode per season where Ultraman fights at human scale. Although in one case it was because his human host was miniaturized, and turning giant cancelled that out. I sometimes wonder how far it could go. Since Ultra Warriors seem to have conscious control over their size, I imagine they could choose to miniaturize themselves (I think I saw that once), maybe go microscopic. And I wonder what an Ultra's maximum possible size would be.