I have been seeing the same problem with the Quickfire TK and it continues with macOS Sierra (10.12) and even High Sierra (10.13). I don't know if this is CoolerMaster's issue or Apple's issue, but I would sure love if someone got to the bottom of it and issued a fix. Does CM ever issue firmware updates for keyboards?
In any case, I filed a bug report with Apple in September 2016 (bug report 28407366). You can do the same at https://bugreport.apple.com. The more people who report this the better chance they (or CM) will fix it.
I have found that the seemingly random disconnection is actually related to the Mac checking for software updates. Here is a test I devised to trigger the problem on my Mac:
(1) I opened two windows with the Terminal program.
(2) In the first Terminal window I type "ls" from the Quickfire TK keyboard to confirm it is working.
(3) In the first Terminal window I type "softwareupdate -l" to force the Mac to check for updates.
(4) In the second Terminal window I type "ls" from the Quickfire TK keyboard to see if it is working (it never is at this point). Note that I did not wait for the software update process to complete in the first window. The failure happens immediately (or at least as fast as I can get from one window to the other and type "ls").
So give this a try. See if you can replicate the problem. If so, file a bug report with Apple. If anyone knows how to get the attention of CM on this problem, please let us know.