If I wasn't looking for a repair or gap filling, then maybe thicker materials that sit on surfaces aren't really needed. If you look at the cyanoacrylate option, there are good ultra thin products. If the wood is well cleaned, it can be carefully applied a little at a time and the grain will 'drink' it in. Multiple passes can be done until the grain won't take any more with a lesser worry about changing the inletting. I'd think a decent epoxy would be tougher though if needed. Best of luck with it.
