Or do communists under capitalism just have to avoid scenarios that involve labor relations?
If your underlings make talk of organizing, you can turn a blind eye when they're under your supervision instead of ratting them out. You have limited poweer, but for the most part, your subordinates will likely view you with a mixture of distrust, hatred, and coercive subservience.
I think that as soon as you go to a managerial position it becomes much harder to do anything leftie/communist. At that point you are an extension of the boss and therefor the company. And as management you are supposed to care about the business/how it is ran first. Employees being a second because you can always get more employees.
Depends entirely on the industry. Like for a small-scale service industry gig, taking a management position can let you help out workers. Especially if you have scheduling power, you can save them from getting shitty shifts or giving more hours when you can. However any sort of district manager above you will probably ride you until you're, but there's definitely room for it.
my instinctual theory is take a management position only if unionization is imminent, like no more than 2 or 3 months away. Unless you can make yourself entirely indispensable somehow and put yourself in a position to make labour-oriented demands.