Many VLANS and php-fpm 100%CPU Hangs web gui
This problem was reported some time ago already:
In my case, I got about 360 opt Interfaces (vlans & bridges), rendering the list of interfaces as a dashboard widget or "Interfaces -> Assign" is really slow, even though I got decent hardware (>10 cores, >16G RAM).
Slow means "within minutes".
So for me 2.3.x is not usable at all.
I had a look on the code and I think the problem is the logic used to lookup the interface details. A single call to getifaddrs() should be enough for a single request to have all details required for all interfaces, instead it is called rather frequently.
I'd love to give more details - e.g. numbers on calls to getifaddrs(), but I'm missing the toopls required to profile (dtrace?) in pfSense.