Its not exactly what you think it is...
Code:
enum {MAX_PROCS = 4};
tProc PermaProcs[MAX_PROCS];
tProc SpellProcs[MAX_PROCS];
tProc DefensiveProcs[MAX_PROCS];
tProc RangedProcs[MAX_PROCS];
None of those are weapon procs, which are handled seperately in the attack code(there is no limit, TryWeaponProc function).
I have never seen PermaProcs used but the rest are pretty obvious.
I have set the values to 50 without issue as well as creating a few types of procs that were not natively supported in EQ(weapon procs added by armor effects for example). There is no client limitation on any of it.