I've noticed that as soon as I started using fire rockets in the raid, I began to receive a message in the console about the long processing of hooks.

Calling 'OnEntityTakeDamage' on 'RaidableBases v1.5.0' took average 2411ms
Calling 'CanBeTargeted' on 'TruePVE v1.1.8' took average 1424ms
Calling 'OnNpcTarget' on 'RaidableBases v1.5.0' took average 1609ms

Maybe the reason is that the entity is taking fire damage and is trying to find a target.
To the problem is probably that the entity is trying to find a target when receiving damage from fire, but cannot find the target.
This is probably an Oxide problem.
Who will say what?

Not an issue, those just mean that it took a comparatively long time to call those hooks on those plugins. This could be a few things, it could either be that the plugins are unoptimised or the server is running slow or out of resources causing operations to be delayed and or slow. 

1) a better machine would help in some situations, but enough players using fire rockets will still cause the issue and this is not viable for everyone

2) optimizing them more would help, but it wasn't mentioned that unsubscribing these hooks can still causes this issue on some machines

the issue is more the fact that the hooks are repeatedly called and absurd amount of times when fire rockets are used on traps