your experiences might differ, but in my experience it has been mentally harder to be around people I knew pre-transition ... I behave in old ways around them and find it harder to be myself, I feel like they know I'm fake or a fraud, etc. and that undercuts my confidence (which is especially important for voice feminization).

That said, I've also had no real drama or issues with coworkers I knew pre-transition... the closest was one of them accidentally deadnaming me in a meeting with people who didn't know me pre-transition, so I was effectively outed in that moment to anyone who hadn't already noticed or heard through chatter

but that only happened once and they felt awful about it, worse than I felt I'm sure

most people just want to know how to be polite and behave correctly, most weirdness I saw was from people just feeling anxious because they aren't 100% sure what is or isn't respectful