The 5D3 can use a newer method of saving full resolution silent stills using lossless compression that solves various issues but memory management is more difficult to control. Until a way to get this working on other cameras I propose allowing these cameras to use the older method of compressing DNGs in place.
When the DNGs are saved using the older method there is a warning, "RAW error, falling back to YUV overlays" but the files are saved. With the current silent module there is no warning but the DNGs are not saved on the EOSM/100D/650D/700D.
I can confirm this behaviour on the eos100D. This older code works with lossless FRSP.
Indeed it does work really well w this older code. Even FRSP Lossless DNG's would allow 2 second intervals in between photos while using ML;s Intervalometer which is rather remarkable. I went ahead to tried 1 second and of course it was too short. :D
Why not adding some printf's to see where it fails?