the poster asked about PLATFORMS for road RIDING not really road racing or macho manning 40mph+ and I think it's more than fair to say to all the maximum optimizers of bike pedaling biomechanics that within a few few minutes any platformer can arrive wherever a clipped in guy can arrive so the need to be clipped is more often than not a matter of vanity and remember a PLATFORMER can walk around in much more comfortable shoes
and there are many $40-$75 pedals if you don't want to commit to a $$$ crank bro