Your question is a bit confusing, but I assume you want to use fork drops in place of standard rear dropouts. If so I can't imagine why, unless you think it would look cleaner.
While it could be sturdy enough (using the right dropouts, and careful placement of the ss's), there's three reasons I wouldn't- the slots are 9mm (but could be enlarged), the slot angle may not be optimum for safety (so you'd want to keep the lawyer lips), and you lose the luxury of having chain adjustments.
I've built two single speeds with standard road drops. Never again. Since there is no chain adjustment, you got's to fiddle with half links, chainring and cog sizing for a good fit. You could run a tensioner but that defeats the purpose of simplicity. Then the chain stretches. I've used both hooded drops, and lugged drops and lopped off the DR hangers. Now it's a bit of extra work to convert them back to a geared setup.
Stick with a track type drop with a horizontal slot.
Any steel frame builders make a lugged steel bike with forkends? I don't want a track bike specifically, just a single speed for commuting that has enough tire clearance for a 32 tire. Caliper brakes.
can't imagine why not. i have two single speed frames with road geometry and fork ends. simplest SS setup i've found. they have 120mm spacing in back, but if you plan to have it custom built you can have 120,126,130, or even highter if you want, i suppose.
Rivendell made two, the Quickbeam and the SimpleOne. They both have fork ends (smart ones with a bit of angle, so you don't have to re-adjust the brakes) and clear 700x40 tires.
If you're quite tall, someone is selling a 68cm Quickbeam on the RBW list...