The 3-1/2 in. SureCorner flexible corner flashing for door and window installation served as a great supplement to the flexible sill flashing for my sliding patio. Hopefully, the combination of the SureCorner and the 6 in. wide Grace Vycor Plus flexible flashing will protect the subfloor/sill and all below it from water intrusion for a lifetime.
I had to replace the 20 year old Crestline wooden (Aluminum clad exterior) patio door that came with my original home. I chose the United 4500 vinyl door for the second installation. In 1997 my builder installed the patio door with no protection of any kind to the subfloor/sill. Over the years water infiltrated and damaged part of: the fixed door panel (not his fault), the door sill, subfloor/sill, the exterior OSB sheathing, box joist, floor joist, insulation (between the floor joists), and the house sill. I had to fix/replace some structures before installing the new door. A replacement job became a repair and replacement job. Good luck with your projects.