Why not just have two sets of pedals? It doesn't take that long to change them, and any temporary platform that you clip onto a clipless pedal is going to be a big compromise in grip.

The one sided pedals don't look like they have much grip either. And then you have to worry about which side is up all the time. No thank you.

I hate those toe-clip cage things. Effing terrifying. They're hard to get into, it's not an intuitive motion to get out of if you need to get off your bike quickly, they automatically flip upside down when you're not in them and get caught on stuff on the trail, if you lock them down tight enough so they hold you in they're impossible to get out of, etc.

Get a pair of SPDs and loosen the tension. They're easy enough to get out of that way. Then keep a good pair of platforms around and just change them when you need to.