Stash Tab suggestion

I got a pretty simple suggestion.
Can you add a thing in the shop to upgrade any normal or premium stash tab to a premium quad stash tab?
Premium Quad stash tabs are just objectively the best stash tab since you dont have to make them public and if you dont they are just premium tab in better.
you can adjust the cost for the upgrade obviously but it would be really nice if we could upgrade our tabs to premium quads.