i ordered a custom piece and made a template.. but i dont know exactly how far i wanted the unit to go back.. so i ordered one to go back towards my crown. If on the day im going to get it cut in and i decide i only want it to back back close o my crown but not that far could i cut the unit and make it shorter? or is this not possible?

ive heard of people cutting stock pieces to make a partial. does this same thing apply?