Screamers are too big a fuel pig for very small excursion carriers because of the no-HEP/notch 8 operation. It also tends to be overkill on horsepower. Maine Eastern wasn't exactly getting peak efficiency out of theirs with how much fuel they burned on a relatively short run, so can't see Conway Scenic much less a volunteer-heavy operation like Hobo using them short of a very short-term rental situation a la Cape Cod Central right now. That said...there are some very big heritage operators out West that run longish-distance trains with large number of cars (Grand Canyon Railway, for example, uses ex-AMTK Screamers) where these would definitely be sought-after. Even with their advanced wear there's no shortage of aftermarket F40 parts, and cheap extra units are a good value for giving the carriers relievers so they can give their top-condition workhorses better TLC in the shop. I could see Iowa Pacific perhaps picking some up, since they own so many excursion carriers they share equipment amongst.
The FrankenGeeps...yuck. Unless somebody can easily de-gunk them by ripping out the problematic microprocessor control I'm not sure anybody would touch those. Those wonky controls are just too big a P.I.T.A. for a skunkworks carrier to want to touch unless they can be downrated. Or restored easily to freight gearing. NJ Transit's glut of dispersal Geeps are a much better value for that. And the shortline freights are starting to get much better aftermarket deals on Class I's & II's dispersal freight Geeps now that the big boys are slowly phasing them out. I could see those being carbody donors for MPI to do up more
MP32's with cleanroomed guts and cabs in the old shell, like they did for SunRail with a bunch of MARC's retirees. Those no longer have anything Geep-related inside them beyond the shell, but if the MC's are that big a headache to try to modify it may be the best use for them going forward.