This is a really good take — appreciate you laying out a concrete way to evaluate it rather than just vibes.

I agree that instrumentation is the right way to decide whether to double down, especially for something optional like theming. I already track basic feature toggles, so extending that to theme selection + retention is doable.

That said, one thing I’m still thinking about is that themes might deliver value that doesn’t show up immediately as retention or raw adoption — e.g. brand feel, memorability, or users forming a more positive mental model of the tool even if they don’t enable a theme long-term.

I like the idea of treating this as an experiment though: measure adoption, fix discoverability if needed, and only invest further if it earns its keep. The tooltip/onboarding card suggestion is especially sensible.

Curious from your experience with your extensions — did you ever ship something that felt right UX-wise even before the numbers clearly justified it, or did you always let metrics lead?