A person who is in a kollel where according to the official rules he has to daven there, as well, would he be allowed to not daven there if there is some reason why he needs to daven elsewhere (e.g., he needs to use the bathroom right before Maariv and by the time that he comes out it is hard to catch up with the minyan, and there are enough people without him)? Or if the davening is too fast there? Or is he obligated to daven there every single time? (Perhaps the purpose of the rule is to avoid hefkeirus, but if there is a reason why he is not able to participate in the minyan, and there are enough people without him, it would be OK?) He doesn’t want to ask the rosh kollel.
It is hard for me to give you an answer on what the rosh kollel means and what he wants. It would stand to reason though, (unless the kollel is small and they need everyone there for the minyan) that if the reason you aren’t davening there is a one time thing, such as that you needed the bathroom, that the rosh kollel won’t mind. However if it is because you don’t like the speed of the davening, which is a reason that will apply all the time, and that he would mind. Therefore not davening there for that reason would have to be discussed with him.