I mean, I am not too concerned and it is your code. The if constexpr is just so much spiffier. You should do what's best for you.

My own use case is that for pre-C++23 (and in particular, pre-C++20) workflows I'm looking to homogeneize the set of dependencies used to supplement the standard library and this looks like a great candidate lib. I already have my own expected, actually, but would rather someone else's who knows what they're doing. Since C++14 is the oldest standard I have to support directly for clients (big improvement: was C++03 before 2021) and it brought in the big changes that made constexpr actually usable, I treat C++14 as a a sorta "C++ LTS" in my codebase.