Comment 6 for bug 1621294

Thank you for sending me your ruleset. On a constrained system I don't see any problems:

$ time sudo ufw disable
Firewall stopped and disabled on system startup

real 0m0.193s
user 0m0.100s
sys 0m0.016s

$ time sudo ufw --force enable
Firewall is active and enabled on system startup

real 0m0.322s
user 0m0.096s
sys 0m0.060s

This is less than .2 seconds to disable and just over .3 secconds to enable. This does not appear to be a bug in ufw per se and seems system specific. I checked if removing the .pyc files slowed ufw much (eg, on Ubuntu 16.04: 'sudo rm -f /usr/lib/python3/dist-packages/ufw/__pycache__/*') and it doesn't on amd64 (which based on your bug description, yours is also).

I suspect your system is under high load, memory pressure, etc. For now, I'm going to mark this as 'Invalid' but feel free to comment if you discover this is an issue with ufw and not a local issue.