From some unidentified point version of Resolume v6 up until at least Resolume_Arena_6_1_0_rev_61231_No_Footage_Installer downloaded today, when saving the Composition the output is interrupted for some period. In older versions I sometimes had output freezing, now I get output blackout. Maybe 3 seconds. Maybe longer.
I generally like to save as I go during a show to better recover from crashes (if/when they happen).