It is possible. Not suggested, but possible. You should have your pitch settings set to the linear from mid stick to full throttle. This should give you 0º of pitch at mid stick. Next, make sure your motor is not slowing way down at mid stick. This is why I mainly fly in IU, just in case. When you are wanting to do a flip or roll, just add some collective so the helicopter is going up, pull back on the cyclic (or what ever way you are wanting to flip or roll), lower the collective to mid stick as you are approaching full inverted. Once you pass the full inverted state, start adding collective to catch it as it comes back to upright.
Definitely practice this on the sim first. And absolutely do not try this without reducing the collective while flipping or rolling. It will pile drive itself into the ground...