My question is: is there any solution o the "double spend" by the inscription write?
If I buy a "bored ape", is there a way to prevent the issuer from minting 1,000 of such inscriptions and defrauding the buyer? Each of them could have some invisible change to trick any SHA256 checks on those.
In short, no. However, you can use the blockchain to see which was inscribed first. This seems to be the way that NFTs are valued. For example, there's nothing stopping me from copying the entire Bored Ape Yacht Club NFT collection and reissuing it on the same chain. It would actually be extremely easy to do and not take much time. The NFTs could contain the exact same links and the images would be literally the exact same images. However, would they still be Bored Ape Yacht Club NFTs? No. So my assumption is that the blockchain would work the same way. Your point is a good one though that the marketplaces should figure out. I'd imagine some sort of search of the blockchain to make sure the metadata doesn't already exist on chain when the items are put up for sale would be a good feature to have.