iRule Proc and Performance

I started using iRule procs in a very big irule.

I have like 30 procs in this iRule.

I haven't noticed any performance issues in my test lab and in my staging environment.

The procs are mostly called on initial session/connection and then cookies are used to bypass the procs.

DO you guys have any advice as to the use of procs. I find them really powerful and they have helped me have a clean nice iRule to do a lot of stuff in combination with APM.

How are the procs managed in ram when they are not called?

Do they get destroyed when the iRule events close?

Are there any optimization options to minimize memory usage since these procs are loaded whenever the irule is called?

I'm using version 12.1.3.

For the moment I'm keeping all the procs in the same iRule.