This is something we definitely want to look at but haven't had the time to prioritize.
It will require significant changes under the hood for these primitives, so it isn't a small change.

Let's say I had a few days to invest in getting radix/form working with radix/themes (not that I expect I would produce releasable quality code).

The core issue blocking radix/primitives from working with radix/form is not immediately apparent to me. Is it an issue with the context's?

What I'd like to do is have an SSR form that is displayed when the user first loads the site (think sign-up page). This seems pretty straight forward (even with radix/themes) using the strategy already laid out. (ie. leverage defined validity "states" with defined messages and then data- states and onChange handlers on the input component)

But I'm sure I'm missing some significant pieces here, mostly just curious.

@jd-carroll I did some small research, the issue with Radix primitives is that it seems like onInvalid event is not propagated, since Radix rendering other elements as button etc, and actual HTML input or select is hidden. On the form you can listen onInvalid with Radix primitives just fine! I feel like you need to pass those events to primitives Root and this should solve the issue.

Another thing you would need to do, is to handle focus properly, because currently Form trying to focus aria-hidden inputs on validation, which throws an error in devtools