I was in a Missouri DMV in Warrensburg MO. and they would not take the mail box number from an Airman stationed at Whiteman AFB. He lives in the barracks and gets his mail in a box from his unit mail room. The reason he did not have it on any official document. He called and asked his 1sgt but no it had to be on an official letterhead to be used. They would not take a fax, email or pdf file but that is another rant.
They used to take the info as to unit verbally from the airman without the need for a PO box let alone an accurate confirmed address.
Missouri DMV's now mail you your license from a central site. They ant to make sure they have a good address but to me have made it harder for a lot of people . They cannot issue a license to you they can only input info for you to get license in the mail latter.
This could cause problems for snow birds and full timers.
I assume before full timing you make a decision as to what your permanent address is going to be and establish everything voting, snail mail, taxes, official state of residence, bank accounts, vehicle registration, boat registration, Gun registration/ cancel carry permit, fishing hunting license , professional license, club memberships with that address. Each person has things unique to them so not one correct answer.
Move to the state you want to use. Rent a PO box and stay in the area for 31 days or what ever it takes to establish residency then get everything switched over before you leave the area.
Do not try and have vehicles registered in several states or have several fishing license as a resident or use multiple addresses for different things.