It is uncomfortable, but it's done. The USCF published a training guide a couple decades ago. The photo at the last chapter (called "Questions") was of The Great On (Eddy, of course), waiting for the race to start, sitting on the saddle, one foot clipped to the pedal and the other solidly, but on tiptoe, planted on the ground, patiently signing an autograph for an attractive female fan.

After I saw that I lowered my saddle a bit and increased the setback.

I understand that many pros are riding with less setback these days.