Instead of using metal pans, the author creates sill pans using fluid-applied. Note: Seams in the porch deck are also sealed with fluid-applied.
Doors are installed on horseshoe shims in a bed created by lines of fluid-applied that are spaced wide enough apart so there are channels between the smushed-out beads to allow water to drain.
The unit is shimmed and secured.
The spaces between shims are filled with backer rod.
After the shims are cut back, the window is protected by painter’s tape ...
... and a bead of fluid-applied completes the inside air seal.