Glad things did not end up worse. I believe someone had a similar situation just a few weeks back and the bike ended up on its right side. Glad you saved yours. I put my bike on the center stand every single day. I did not used to until the wind kept blowing peoples bikes over. There have been a couple instances where my boots could have slipped off the center stand foot pad because I did not take the time to ensure my foot was centered. I get in a rush sometimes and don't keep my foot completely level and centered. I have found that is the key.
1. Rubber Boot (You Mentioned). I've never seen it but they may be out there.
2. A piece of self-adhesive non-skid tape. I have heard of guys doing this and it works. It might need ot be replaced once in a while. They work on surfaces that get wet. Just think back to the days when people put them in bath tubs. You can get a role of take at Lowes to $9
3. You could rough up the pedal surface with a file or grinder and repaint it.