I've found it quite annoying, I'm considering going the other way for my personal project from Go+Templ+HTMX -> Flask + Jinja + HTMX. Still undecided though.
I feel like Go is quite verbose and defining templates in Templ feels painful.
I made the switch from FastAPI + Jinja + HTMX to Go and embedding the HTML into the Go binary directly... it's very nice being able to run the apps without an interpreter. I'm able to make ~5MB sized containers to run the full stack
there's a performance increase too, but these apps I'm talking about are so simple it's not enough to really notice. objectively FastAPI is really good and makes running a simple site so easy, I'd still recommend to most people using that.
I feel like Go is quite verbose and defining templates in Templ feels painful.