I don't know who did this first. I remember seeing the idea come up multiple times in the 5 or so year's I've been paying attention. Generally the same solution has come up most times. It's easy to make and the obvious solution as an alternative to relocating the piston mount on the frame side or moving the brackets on the lower control arms up front and the rear axle. I think you might be the first to actually sell them commercially if you do sell them.

The general reason that they were not pursued was that the travel range of the suspension in the front isn't changing with a lift and the OEM system can cycle through the entire range of travel already. So lowering the sway bar to a different static position probably doesn't actually do much good and ends up causing interference with skid plates.

The rear does appear to help quite a bit with clearance of the track bar. I think most people chose to relocate the track bar bracket an inch or two higher as an alternative because it also fixes the geometry problem with an unlevel track bar. I do think this solution works great in the rear for a situation where you want a bolt on solution that's easy to reverse and you're not going rock crawling where you'll be dragging the rear sway bar on the rocks. That probably encompasses most lifted 4Runners. I suspect a fair amount of folks would probably use them.