Recently saw Michael Kennedy's presentation at Python Web Conference where he talks about this. He also has a course on using Flask + HTMX. Even if you don't take the course, you do have access to the github repo for that course.
He wrote a small library extending Jinja that does what you're referencing here, I believe. It's a little different than Jinja macros and include (you can reference the github issues for a discussion on that).
https://github.com/talkpython/htmx-python-course
He wrote a small library extending Jinja that does what you're referencing here, I believe. It's a little different than Jinja macros and include (you can reference the github issues for a discussion on that).
https://github.com/mikeckennedy/jinja_partials
Maybe that's what you're looking for?