Hi,
so do I read your question correct, that you want to know if a slow request (taking 2 minutes) will impact the performance of the system for other requests?
That mostly depends on the actions this request does that during these 2minutes. If you create a lot of content, it will probably have an impact, because many of these write operations are probably triggering other actions (JCR observation, workflows, ...). But if it just sits silently waiting for a backend call to complete, you probably won't have any impact.
have you tried it already?