so it turns out a .makerbot file is actually just a .zip folder containing some pictures, a meta.json file with all the settings and parameters, and a print.jsontoolpath which is just a regular .json file as far as I can tell that contains all the actual movement instructions. Pic related is a 2mm x 10mm x 0.2mm structure i sliced on makerbot print.

Still trying to decide if I buy 2 basically new z18's with new smart extruders and replace the control board of one or more of them with something klipper compatible and get a machine that is super great build quality and sturdy and with modern features for a really low price but have to deal with actually retrofitting it, OR do I get an existing modern large format printer that maybe has even larger build volume but probably wont be enclosed or as well built and/or will be more expensive...

Not sure what to do with this information but it seems interesting. At least it isn't a completely unreadable binary file or anything.