Apparently the DTV wouldn’t work, because you’re not working remotely in thailand, I’m also working offshore and onshore outside of thailand , I enquired about this option also, I’m married to a Thai so I can qualify to stay via that method but the DTV sounded a great option for me since I’m less than 180 days each year in the country,, your best bet would likely be visa exempt entry for the hassle free option, not sure about the e-visas since I’ve never had to apply for them
I think you’re forgetting your Biometric data will already be entered into the system when you entered , but then maybe if you were to exit then reenter on your online application you might be ok,
As i understand a long term visa is a requirement based on my experience anyway, lived 16 years here and that’s what I’ve found,,
however there are workarounds that can get you a bank account,
I have 3 different th bank accounts and was denied at a Bangkok bank in one of the provinces when opening my second account, this was despite having a 1 year multi entry, I just asked them to contact their head office for clarification on the requirements , the application was then very quickly approved.
Maybe it’s worth trying from that angle, insist they seek clarification from their head office, many staff are uncertain of the requirements so easy option is “cannot”.
Maybe worthwhile him checking up on but I understand he can get an IDP lasting 1 year before leaving UK, legally he can drive whatever classification on his IDP, I think the IDP entitles the holder to drive up to 90 days at any one time , this should be ok as he’ll be exiting and rendering on 90 days.
I was turned away from trying to sit a driving test in Philippines a few years back, the staff at the test center told me that since I wasn’t gonna be in country longer than the 90 days (even though I told them I’d be back) they said my IDP would suffice and a ph driving license not needed.