I think this is actually part of a larger issue - traced numbers in Reactant, for example, are also subtypes of Number, so it’s hard for user code to say “I need something kind of like a Real here” without taking on a heavy and very specialized dependency. We have a similar problem in Static, where the static integer is a Number not a Real. And probably in other places too.
I think we can make a super-lightweight package for “unusual numbers” (and subtypes for the quantity, traced and static case) to solve this in a generic and user/dependency-friendly fashion. I’ll try to put together a quick prototype with proof of concept PRs on Unitful, FlexUnits and DynamicQuantities, Reactant and maybe Static as well, then we could iterate on naming, structure, etc.