My report: Nice!
Hot shower -> Simpson Major -> DR Harris lavender shave stick -> Feather AS-D1 with a new Feather blade propped up by an old Astra "shim" underneath (with the handle snug).
Although the blade exposure is greater, and although the blade is flatter, it is still a very mild and intuitive shave. No fiddling with angles was necessary (instead, just listen to the blade sing as it slices whiskers). DFS in a few passes with some touch up. No weepers, nicks, cuts, or irritation.
Tomorrow, I think I'll try stacking two shims for a slightly more aggressive shave and see if it will cut even closer.