My company instructions are to use the passcom talkback only to find out what the problem is. You wouldn't get into a conversation about it. Most of the time the person using it either doesn't speak or you can't hear them clearly anyway.Is the driver allowed to have a conversation (potentially a whole string of conversations with passengers in different coaches) while driving at speed?
On the trains I drive the passenger information is really basic and only lets you skip one station at a time. If you were missing out four in a row - A B C D - you'd need to press the button four times to skip A, then B, then C, then D but while you're doing it the system would show and announce "The next stop is B" then "The next stop is C" then "The next stop is D" then "The next stop is E". It would be much less confusing just to turn it off and let the guard make manual announcements.