What is the best way to create a Roth crypto account held with AltoIRA, which has no interface to Quicken? I am fine with doing manual tracking, I just want the approximate current balance included in my investment accounts if possible.
That's simply an offline investing/Brokerage account, named however you want and with appropriate tax attributes set.
Then you'd transfer cash into that account and BUY the crypto. And, even though you can't download positions into the account, by properly setting the investment (Which crypto are you buying?), you CAN download the quote for the crypto.