BuddyPress.org

Getting the original post’s time stamp to stay at the original value and show the most recent time stamp on the latest reply, all the while having it bump.

might be possible… if anyone wants to try running something on this filter:

apply_filters( 'bp_activity_time_since', '<span class="time-since">' . sprintf( __( '%s ago', 'buddypress' ), bp_core_time_since( $activities_template->activity->date_recorded ) ) . '</span>', &$activities_template->activity );

check if the activity meta key ‘bump_date_recorded’ exists and swap it in for the time_since

(i’m not sure about the second question)