You can trade bit.gold on bitshares.org. There are some cryptos coming for the PM space but I don't have a lot of faith in that... you still have the problem of trusting the guy running the vault and guess what? I don't. Been in this business too long to trust that industry.
If you don't hold it, you don't own it. that goes for gold as well as private keys.
I one hundred percent agree, can't be overstated. The fundamental position in pm's should be physical. My interest in crypto's and pm crypto's is for speculation only (like say, mining shares.)