When I rehabed Solsken, I used a 1/8" Dremel routing tool bit to rout out all the above water cracks - a big job. What I found was that once I went through the gel coat, the glass was very solid, so that if the cracks were caused by WSM, it didn't appear to have any effect on the underlying glass.

Having said that, I don't know if I could have seen a hairline crack in the glass resin itself, but if there were leaching and/or blistering, I would have seen that, I presume.