Mounting plates to attach a hot end to a standard Wade's + OpenX combo. -Solid Plate- The solid one well do the job fine, though you'll have to rout out some of the wades in order to get nuts in. I designed it to use mainly as a template for an MDF or aluminum version that can be hand cut and drilled.
-Printed Plate- A printed mounting plate is an interesting and difficult problem. It has to deal with the hot plume coming off the hot end, as well as the heat conducted up the threaded rod supports.
I made the slotted version for that reason. hopefully the heat won't get trapped under the extruder plate because it will escape through the slots(though at the moment the slots will be blocked by the wades on top of it), and the slots will also help stir up air, keeping the plastic of the mounting plate cool. I'm not sure whether it will work at all when printed, though.
Another experiment is to put a couple of layers of aluminum foil on the underside of the mounting plate. My theory is that it will protect the plastic from the hottest part of the plume, and distribute the hot spot over a wider surface are. The slots will then act like a heat sink, increasing the surface area of the mounting plate and hopefully preventing it from getting hot enough to melt.
Possibly a bigger problem is heat conducted up the support rods. I think a cardboard washer (just hand cut) will probably help a lot. However, there will still be metal-to-plastic contact where the rod passes through the holes. if this is an issue, I'll redesign it in order to accept some kind of insert (made of PEEK, PTFE, ceramic, whatever).
I doubt you will be able to print this in PLA and have it work with ABS; the plume is probably just too hot. But PLA might just work when printing PLA. And a PLA plate will probably hold together long enough in order to print an ABS version.