I don't retrohale.How are you retrohaling?
Since catching pneumonia 10 years ago which affected the top of my lungs, I take as few risks as possible.
I smoke by breathing in through my nose with the back of the throat gently but firmly closed, and then out through the mouth.
It works well for me. I get plenty of flavour and a nic hit from the first breath.
Pipe will usually stay lit for the whole session. No problems.