Quoted from radium:
I’d be afraid to put anything water-based on it, would worry sanding would open the grain and make it want to move around again when wet. My space station cab was planked like that but I just built a new one.
FWIW, Jeff Miller (Pinball Pimp Stencils) was the one who recommended Durham's. He said he uses it all the time as part of his cabinet painting process.
I'm going to work on stripping the rest of the paint this weekend and then touch up some edges with wood epoxy. That'll give me more time to think about how to address the planking (Bondo, Durham's, Fix It All, or other). I picked up some Durham's today and practiced on some spare plywood with different mixing ratios for viscosity, from thicker putty for filling in holes to thinner glaze to smooth out scratches. Not too bad. It's more flexible than bondo in that way, and more importantly it does not set as quickly as bondo giving me more time to work. Within 20 minutes it was set hard and touchable. In under an hour, it was sandable. 4 hours later, hard as rock. At that 4 hour mark, I poured a little water on it and it did NOT soften up....still hard as a rock.