>In my observation, very few users require an accurate query plan for temporary tables to
perform manual analyze.
Absolutely not true in my observations or personal experience. It's one of the main reasons I have needed to use (local) temporary tables rather than just materializing a CTE when decomposing queries that are too complex for Postgres to handle.
I wish I could use GTT to avoid the catalog bloat in those instances, but that will only be possible if the query plans are accurate.