I bought a lot of profiles, which I saved in a directory structure on my harddisk. Trying to import that directory structure (with the .kipr files etc.) I just encountered several crashes of the whole Rig Manager unfortunately! ( Using Rig Manager Version 3.0.131.16339 on Windows 10 PRO x64 German, Version 10.0.18363.959 ).
Maybe there is a more robust import function I did not see (?), but I used the Windows Explorer drag'n'drop method, adding the directory structure to a Folder below my "Local Library" (All Rigs). For some directories that worked very well, but sometimes the whole application crashed!
Being an IT professional myself I can give you some more specific descriptions (hopefully it helps):
1) What I first realized, debugging the issue, is that non-ascii special characters in file or directory names are not handled well - instead these lead to crashes (at least its not hard to fix that manually). I would strongly recommend though to introduce some kind of exception handling here in the programming routine with two results: a) Just skip problematic files you cannot handle. b) I would definitely report the number of errors / skipped files, so the user knows that there are issues and can try to fix and repeat (ideally with some extra text information about the type of issue, too), but please try to not let the application crash! 
2) In my case I could reproduce, unfortunately, that in a situation with a directory structure with different sub-directories and a lot of profiles the Rig Manager import did not work consistently for me: For instance, importing directories A....1, B...2, C...3, D...4 all together, assume the import crashes somewhere at C...3. Ok, then when I restart and check again to import just A...1 and B...1(which were already successful) that works great, app telling there is nothing new, so far so good! Then I try to import C...3 again, crash! Not nice. ...but strangely though after 1-2 new restarts of the Rig Manager chances are that it is now working in a new retry, I observed that a few times now. Suddenly it imports or suddenly it detects that it already has the files but at other times it crashes, when basically there should be nothing different.
This is really an issue, because the application should behave consistently, not sometimes importing, sometimes not, without changing anything at the file or directory level - hard to tell what is going on.
--> At the moment it seems there is no log file reporting last steps, errors or something like that, is there? (Did not find one). It would probably be a good idea to including a logging mechanic in the application writing exception messages into a file to make debugging easier, don't you agree?
Thanks in advance!