If it were me, I would parallel the NC contacts on the limit
switch with a set of NC contacts on a pressure switch that
senses the pressure on the triggers. Your holding relay
would then not drop out until you achieve full pressure on
the trigger line. This setting can be set high enough so
that the trigger operates before this setting is reached
thus giving you a delay. If needed, you could put a
restricter in the line to the pressure switch to tune the
timing.