When changing / upgrading the PHP version for a site (8.4 -> 8.5) a new fpm 8.5 pool / socket is created. But the 8.4 pool config / socket is still available and loaded into php-fpm 8.4, and that still is using memory that is completely wasted because the pool is not used.

I see that now when i changed PHP (8.4->8.5) versions. I have min_spare_servers and startup_servers higher than the default so the 8.4 pool is using a lot of wasted, unused memory.

Suggestion: when switching PHP versions for a site, ask the user if the old PHP-FPM pool can be safely deleted. Or create a new insight that checks for unused PHP-FPM pools. A insight is the best solution i think, so the user can verify the pool config if something needs to be copied over to the new pool.