Namely, the Terra shatterer / mana storage bars above items.

Same with lexica botania inv-lookup, by the way.

I'm not really sure how to solve this without reimplementing half of the tooltip resizer

Talking to Mezz about it might be a good idea, since he's the one which made the resizer :)

Yeah I know where it's done (in GuiUtils) but trying to find a way that wouldn't involve copying half that class (ping @mezz?)

Not sure. How were you doing it before?

The tooltips aren't written with this in mind at all. You're probably best off copying the logic. Keep in mind that guis can override drawHoveringText with their own. Also many mods have their own tooltip render methods (Logistics Pipes comes to mind) but hopefully everyone can unify under the GuiUtils one now that it's accessible to everything.