Many of the CMRAs are indeed located in states without income tax such as Nevada, Texas, and Florida. If the taxpayer's sole tie to the state is the CMRA, most states will probably not construe that as establishing tax domicile in the state. However, watch out for VA, which takes the position that having resided therem your tax domicile remains VA until such time as you establish tax domicile in another state. CA includes among the factors it uses to determine tax domicile whether the taxpayer uses professional services in the state or even has friends in the state.
My CMRA, which I recommend, is in FL: sbimailservice.com.
If you are still in the US and planning to expatriate, you should consider changing your address of record with financial institutions to your CMRA before leaving. Then if they question it, you can still produce a utility bill with your name on it. If you don't already have a Google Voice account, you should get one now, since it is easier to do if you still have a US cell number. If you have banks and brokers in the US with whom you will want to connect online, you would be well advised to get a Virtual Private Server with a US-based provider such as AWS, Google Cloud Platform or Azure. Then, when you want to login to your financial account from abroad without provoking the IP watchdogs, you startup and login to your VPS first and from there login to your financial account. These days a VPN no longer fools any website that cares to know.
Do your research carefully before you leave, since your options once your gone will be reduced. Make sure you have several bank accounts, brokers, and credit cards, for instance.