If meps only has certain amount of days to process a prescreen per Mepcom regulation why do they take so much longer ?

Josh Alien As you have been correctly informed, dont confuse processing time with response time.
Response time is based on several factors, from network availability both MEPS and the systems they need to use to screen the application, as well as the recruit they are screening. Some things they may need to confirm, denied for, waive for could take days or weeks to longer. Both internal decision making and outside agencies they are waiting on a response form, so MEPS can compile the pre-screening reason and send it to the recruiter.

So your doing the right thing, keep in contact with the recruiter often but not pestering....He is at the end of notification not part of the screening process...he wants the response back as much as you do

Processing and notification are two different things. Just because you did not hear anything does not mean they did not process it. Check with your recruiter.

the key is process- nothing says anything about a time limit on approval, back logs higher up, etc, Welcome to "Hurry up and Wait".