I know there are various approaches to minimizing cold and or wet feet. My question is about only one of those approaches: in particular, Does anybody know if the under-strap and/or the soles of booties/overshoes get chewed up or even ruined by the pins on some flat pedals (such as mine which are Raceface Chesters)?
To echo what was said above, the point of those is really to allow for the use of a clipless cleat. I tried them once with normal shoes on flats, but as you seem to suspect, they just get chewed up.
Better to just use a warmer shoe. I use goretex hiking shoes when conditions are cold and wet, and Winter boots for fatbiking in the snow.