I'd love for Lena to have more casual sexual encounters, the problem isn't really that there is an issue with having less developed options available, the issue is that there are external factors that makes the options available unattractive.
For example Mike is off limits because he's in a relationship and Lena knows it right away. If Mike had been a bigger asshole and kept that fact secret I'd have been more inclined to do his initial scenes since he'd just be a guy Lena can fuck.
The whole Mark/Holly stuff is kinda weird for me to play too, since at this point Holly is more sexually explorative than my Lena, so she should no longer really be asking her for advice