I can tell you from unpleasant experience that Speedplay frogs don't work without the proper cleats. Shimano MTB-type SPDs work, sort of.

A few weeks ago I fitted a pair of quill pedals with toe clips and straps to one bike just to ride a mile or so on an errand and wanted to have regular shoes. What a surprise. Even with clips and straps, I pulled my foot out at least a half-dozen times and had to be very careful how I pedaled the rest of the trip. I guess I've gotten so used to being able to pull up and back I didn't realize how ingrained it has become.