Якщо ви одночасно запускаєте Tor Browser та інший браузер, це не вплине на продуктивність або приватність Tor.

However, be aware that when using Tor and another browser at the same time, your Tor activity could be linked to your non-Tor (real) IP from the other browser, simply by moving your mouse from one browser into the other.

Or you may simply forget and accidentally use that non-private browser to do something that you intended to do in Tor Browser instead.