Does a PACE request make any difference to the period under Rules 161(1) and 162(2) EPC?

A PACE request does not shorten the six-month period for replying to a communication under Rules 161(1) and 162(2) EPC. Unless you have waived your right to the communication altogether, this period can only be shortened by filing an early reply in which you explicitly state that you will not use the remainder of the period to file further amendments.