Only have done one laminate over 3 tab and I hope it will be my last. Home owner tight on funds phone book job moving in less than 5 years deal. Dropped the tear off charge so low figured it was the way she was going.
Removed the ridge, vents and cut the overhang to be flush with the cedar and installed drip edge and ran them at a 5 5/8th in exposure. If there were any curled shingles the corners were cut back a few inches.
Tried to explain the thick and normal rows to the home owner but she was dead set on a roof over, her neighbor had one done recently.
In the past 4 years all tear offs have had laminates but on a roof over a three tab may look better. If you could find English laminate shingles and run under the original shingles it would look best.