Great question... I wouldn't say my FemDom interests have evolved but there have been instances where fetishes I didn't know I had have absolutely been shown to me by Dommes. One was tattoo worship (especially foot tattoos) and lately one Domme has systematically been creating a smoking fetish.

Basically, I have always liked lighting a Domme's cigarette as a service thing (which made me start to carry a lighter whenever I was serving). Then, this Domme, would have me run out and buy her cigarettes for her. Then, she started having me not just use the lighter to light them but would have me get it started for her by lighting it in my mouth (which meant the first puff as well). Finally, this past visit, she put on this erotic show while ordering me to get on my knees & masturbate to her in an adjacent room... With part of the show being her smoking in a very sensual way.

On the flip side, however, I have had an extremely similar experience with sadism as you did with strapon. My sub is a huge painslut who loves degradation, bruises and marks (I am the polar opposite in my own submission). At first, I just couldn't bring myself to do things to her that I hate myself. However, over time, her amazing reactions to my brutality has made me enjoy being incredibly sadistic and cruel with her, which I never thought was possible. i have no idea if this would translate to my playing with another sub but my perspective had definitely changed over the time we have been together.