What I read about the shared files is that we can perform, clean or transform the shared files, with a CMD command, I used this command to clean and transform, when the shared files are not working is for example when the server where it is installed the QlikView server and suddenly the server got a shutdown or there is a cut of power or there is intermittence in the internet these files get corrupted, so with this command you can clean it or transform, by the way, to transform you need to have installed the 12.20 release and you can manage big shared files like 2 GB and they should work better.
There are other functionalities, but I couldn't find anything about concatenate, please see the following URL with all the information.
I'm afraid there is no supported way to do that. The main problem is that different bookmarks and server objects might have the same name in two different files, so, by concatenating the files you might end up with bookmarks having the same name (and, therefore, only one will be shown).
Daniele - Senior Technical Support Engineer & SaaS Support Coordinator at Qlik If a post helps to resolve your issue, please accept it as a Solution.