Let's say  I dump a yet undumped disc to send to redump, Can I include an external link for the iso in the new disc post or should I just upload it somewhere else genuine question because i can't find much info about it, and the mia lists confuse me even more

No, please do not add the iso into any new disc post.  Redump does not store or share any game files, just the metadata / dump information. 

Additionally, redump does not "manage" or otherwise have any involvement in what individual dumpers choose to do with their game files after dumping. 

The MIA lists are lists of what is believed to be MIA based on lists that are shared, but it is not something that we track or manage here directly. 

If an individual wants to address an MIA or otherwise do something with their game files, that is of their own discretion in terms of what they do and where they share information.  Some people may choose to upload data to the Internet Archive or various other places, if they so choose.

Hopefully this helps to clarify and explain that redump does not store or manage those files in any way.

noted