I think this might fall in a realm that even Rudman couldn't figure out.....
Nonetheless I did some further tests last night. i used easylith and at first it was fine, then the splotching started. After some earlier reading, I decided to add some KBr to delay the lith effect. Well this made it require more exposure. Which might be part of the problem.
I also went back to the Arista powder lith mix and added more B(has the KBr) than A and had the same issue right away. Then I decided to use more A than B and it was good for a few prints and then the splotching started...

I think the emulsion of the paper doesn't like the ambrotype laying on it for very long. The longer the worse it gets. Going from problem 2 into problem 1. As the bromide starts to build in the developer this problem gets worse and worse. For some reason the Arista shifts yellow rather quickly and assume it getting to that state quicker. If I add lots of exposure (time the glass is against the emulsion) it seems to get worse and worse.

The other papers I've used a lot are fomatone mg and fomabrom. I believe fomatone is considered a contact paper and fomabrom is semi-matte. I got the glossy version of MGWT. I'm wondering if the glossy surface and it being an enlarging paper have created this problem. For whatever reason, as the dev exhausts (Bromide increases) it gets worse. Which has me wondering if the semi-matte of MGWT will do the same thing.....

I don't want to give up on the paper for contact printing ambrotypes because i have had some nice results when it works. I also realize I might not get much help because not many have done this exact combination.