My pal lives in Soi 11. He gives a running commentary in a private group we have. It is quite funny. He notices shift changes and how long it takes the new ones to realise he lives there and not to offer him their produce. :-)
If your TM30 gets registered when you get to CM you should be able to do it there. All I have handed over at the window in CM is passport and TM30. Each time he puts TM30 to side and never looks at it. They scan your passport and all info they require is there. PS: it takes a few minutes in CM Airport Branch. Has a drive through if in a car or on a bike.
Anonymous participant They can reject your application. They can see on their system if you are back in Thailand. Look through previous posts about this. They can ask you to prove you are still in Vietnam. If you are a remote worker what is the need to rush back to Thailand is a question they may well ask themselves when assessing your application.