The only undesirable is anything forced (with anyone) on either Alex or Sarah. Since all of that is avoidable, and the other scenes we've had do not involve Alex or Sarah, we're golden so long as that doesn't change. Dev said he had some intense scenes with Neil planned and the implication is that they will involve Sarah. It's understandable that he would want as many people as possible to see those scenes, but the way he worded it was quite clear that they wouldn't be forced upon us.
I might not like Neil, but that's because of his malicious (as far as the POV marriage goes) intentions towards Sarah and disregard of Alex in that equation. I'm fine seeing his scenes with other women, even if I might want my Alex to pursue those women (e.g., Abigail). I'd rather not see them, of course, but in that example, I'm focused on Abigail, not Neil!