@Ghersic This is the kind of thing that can only really be done with DownValues, although you could try to add a "parasitic" UpValue that attaches an UpValue to whatever is calling it

I've often wanted a $UpValueEvaluationDepth option when doing math stuff that I could set higher, but I understand why WRI doesn't have such a thing

@b3m2a1 Thank you. I think a value like $UpValueEvaluationDepth would be very useful too, though I can see why they don't have it.

I'll consider the parasitic UpValue approach and may ask a question on this.