Replying to Filling holes with jb weld

I bought a pair of praxis pow boards that were attempted to be mounted with inserts but the previous owner messed up one hole and filled the holes with jb weld. Keeping in mind these are bigger holes for inserts, should I bore them out and put solid plugs in with epoxy/jb weld or is the jb weld good to hold?
Also, anyone ever mounted these things with two sets of inserts? I may want throw inserts on but they are big holes and don't want to Swiss cheese them with all insert holes.