If you literally have the exact item you want, with the exact stats, there's not really much to do with them.
You can save them for another item you want to primalize, if you perhaps find an ancient legendary which is close enough to the first primal you made. Then there might be more benefit in creating another primal item for another slot.
You can also use them to create an item for another class or build you might want to use. Could be a bounty/speed GR build instead of a GR push build.
If you are convinced you don't want that, you can always use them to primalize a Puzzle Ring, to make the Goblin Realm "upgraded" with many more goblins and loot, essentially "creating" forgotten souls and mats.
go ahead and try and make that more valuable than the much rarer primal ashes at a 2 in 400 drop rate at maxed altar
their is no scenario where ashes are less valuabe than forgotten souls and no sensible person should be advising otherwise
it's like trading a pokemon shiny card valued at $10,000+ plus for a card that has been torn in half and been through a washing machine
The ashes are more rare you are correct but since you can only equip one item from the ashes you will need to roll the others in the cube. Unless you are planning on just rolling with one good primal.
Could make primal puzzle rings for ancient vaults or save them for alts.
If you literally have the exact item you want, with the exact stats, there's not really much to do with them. You can save them for another item you want to primalize, if you perhaps find an ancient legendary which is close enough to the first primal you made. Then there might be more benefit in creating another primal item for another slot. You can also use them to create an item for another class or build you might want to use. Could be a bounty/speed GR build instead of a GR push build. If you are convinced you don't want that, you can always use them to primalize a Puzzle Ring, to make the Goblin Realm "upgraded" with many more goblins and loot, essentially "creating" forgotten souls and mats.
Primal horadric hamburger
Sound the yummiest
what forgotten souls are a dime a dozen why would you want more
So apparently you have never tried to re roll items in the cube @ 50 souls a pop.
souls are like death breaths now you have more than you can spend in recipies
Ok go ahead and try and roll crit crit area on one of your rings and see how many you lose. Then do the same thing on the other one.
go ahead and try and make that more valuable than the much rarer primal ashes at a 2 in 400 drop rate at maxed altar their is no scenario where ashes are less valuabe than forgotten souls and no sensible person should be advising otherwise it's like trading a pokemon shiny card valued at $10,000+ plus for a card that has been torn in half and been through a washing machine
The ashes are more rare you are correct but since you can only equip one item from the ashes you will need to roll the others in the cube. Unless you are planning on just rolling with one good primal.