Indeed. Gapcoin's value is undoubtedly, backed by Math ...  

We can assert that all prime gap records attained by Gapcoin do add to the value of the entire blockchain.

However, this perceived relationship between proof-of-work and value is somewhat unquantifiable in reality.

In terms of Gapcoin, if we consider 'the block' which currently holds the record for the prime gap of maximum known merit - do said coins at this address hold a value above other coins on the chain? In reality, probably not. Things are only worth what someone is willing to exchange them for at any given time. Moreover, auctioning the private key / wallet for the address also carries 'risk' for the buyer, detracting from value or worth.

If we consider transfer of said coins, in this regard, then the only real claim of additional value is perhaps linked to the origin of the coins. It has been asserted already that Bitcoin's of a known questionable origin (or tainted coins) may carry an (actual or perceived) reduced value over coins produced by new blocks or those with a determined 'clean' origin. This concept was developed in Zcash where "All coins are created equal.", due to the ability to hide the origin of coins via shielded addresses.

TBH most folks considering or using Gapcoin as a currency probably won't really care a jot in this regard, in exactly the same way that most users don't know or don't care about the cryptography which underlies Bitcoin.

You are 100% correct though. Gapcoin has two products! Gapcoin's and Prime Gap records ...

In fact, this blockchain has real Agency - https://en.wikipedia.org/wiki/Agency_(philosophy)

...

- https://cointelegraph.com/news/you-can-t-ban-blockchain-it-s-math-a-talk-with-jimmy-wales

Cryptocurrency is not a boat.
Your right to Entropy - https://en.wikipedia.org/wiki/Entropy_(information_theory) - (your right to be unpredictable) is not a boat ...

... boat, boat, boat, boat, boat, boat, boat, boat, boat, boat, boat, unicorn, boat, boat, boat ...