I take you mean the sequence animations that are built into the model of the ragdoll. If the ragdoll's model doesn't have those sequences (i.e. there is only the idle or ragdoll reference pose sequence animations and nothing else), then it is not possible for this tool to be able to play them. You can also see this to be the case with the Animated Props, which also searches the ragdoll's model for sequence animations to play.

If a ragdoll doesn't have sequence animations, you can still play their Stop Motion Helper animations on these ragdolls if you have the animation file located in the directory located in garrysmod/data/smh/. I think this is the closest you can get to playing miscellaneous animations on a ragdoll that may not have any by default