Originally Posted by slyder
Will this adversely affect the inside of the board is my question...
If it does, it was going to happen anyway.
Screw inserts are basically just glued into place. PB Blaster is a rust catalyst. If, for some bizarre reason, it it gets in and around the insert and then , for some bizarre reason, weakens the glue/resin, then the freeze/thaw cycle of melted snow is going to do the same thing.
Personally, I'd try PB Blaster. And then a whack with a hammer. And then some heat. After that's it's game on...drilling it out and re-threading, etc. I've even been known to tack weld a screwdriver bit on, but usually, by that point, I just want to win.