Open all 13 and most 12 HCP hands and 1c could be short so 1d always promises 4+
3rd/4th Seat use rule of 15 to consider opening
1NT is weak 12-14 and 15-17 in third and fourth seat
A reverse has 18+ points and Lebonsohl is available breaking the relay shows 21 points
Link to Montreal Relay
Link to Precision