I haven't seen this error before. All four of your crash dumps (including the V2 one) say "Crash reason: 0x40000015" which unhelpfully means unknown software exception.
The one hint I have is that all three stack traces have this :
11 LeapSvc64.exe!xs::xs_abort(char const *) [err.cpp : 71 + 0x1d]
rip = 0x00007ff6834d4241 rsp = 0x00000076b22ff5a0
rbp = 0x000001b5cd694d90
Found by: stack scanning
libxs is a library only intended for supporting our old transport in V1 applications, so you probably don't need this feature. After your service has been shut down, you can try running manually with:
cd C:\Program Files (x86)\Leap Motion
LeapSvc64.exe --support_xs_transport=false --run
If this successfully gets the service to run longer, you could then put the setting more permanently into C:\ProgramData\Leap Motion\config.json
and restart the service, then reopen config.json to make sure your changes were properly formed and stayed there.
However, that's a big if. It's also possible that "Could not obtain information about a completed frame" is caused by something entirely different.