Honestly I just used word doc and drew a Map and printed it. I've been doing thos for 17 years. They just want to know how to find your home incase they need to surprise visit you
Do your 90 days at the new office and report your new address to the new immigration within 24 hours. Your next visa will be done at the immigration office where you live. Hua him has it's own immigration.
Cambodia seems to be the only one allowing it now. My friend just had to cancel his border run through Laos and then cancel the one for Myanmar. He was able to do Cambodia through Sakgeo