Every school I have ever worked in or had my four children allocated five minutes for parents evening.
Appointments always run over, meaning the teacher doesn't get chance to go to the toilet, grab a drink etc. Five minutes isn't enough to go and log into a computer, sit and write an email, and then get back to the parents there in person.
Before the meetings they will be preparing their notes, having something to eat/drink/use the toilet/tidy up/prepare for thr next day as they'll have been teaching all day and will be teaching the next day.
After the appointments, which as I said almost always run over, they'll want to go home to have dinner, see their own families, and get ready for the next day. Ir wasn't unheard of for parents evenings to still be going on until 7pm in schools I have taught in, then many of the teachers still had a long commute home.
While flexibility is important, you can't expect teachers, who are very often parents themselves, to keep putting themselves out more than they often do.
If you don't have concerns, don't sweat it. And you won't be talked about in the staffroom because staff, if they're lucky enough to get to the staffroom for a break, they have much more important things to talk about.