Interestingly, the last new module design they have on their (clearly unsecured!!!) website is from early 2020, which is a big switch from their prior consistent introduction of new modules. I can surmise a guess as to why they might seem to be MIA, though, but I'm not going to get political on MG.
My suggestion would be to get in touch with Rat King directly instead via their website at http://ratkingmodular.com/ . You might also find some useful fixes in their own assembly directions, which might or might not be the same as the ones Synthrotek provides. Good luck!