Perhaps if you say which immigration office you will be using, hopefully people with past experience at that office will comment, if the office you intend on using is not far away, just go and ask them, what they will and won't accept.
The general thinking is why go through all that stress to apply with all those documents for under the workcation?? Just apply with the softpower option?? And if you stay in Thailand permanently you will get drawn into the tax system, call me paranoid but, they could be saving all that financial documentation, as future evidence if you don't pay tax on it 🤔
lots of DTV applicants have only borrowed the money to get the visa, and returned it once the visa was granted, and have no intention of doing an extension, and will just do a border bounce, because of the fear of being asked to show any evidence again, I think it just attracts younger less irresponsible people, I don't understand the Thai governments thinking with the DTV, it just basically is allowing anyone free access to Thailand for 5 years, whether they have money or not, I don't think it's a good thing for Thailand overall.
I've heard it's best to get your UK pension sent to wise into your GBP account, turn on interest payments, and just transfer as and when needed into your Thai account.
If possible open a wise account, transfer from your home country account into wise, and then into a Thai account, there are visa agents in Pattaya that can assist you with opening a bank account.
You seem to be concerned about a very long trip from Pattaya to Cambodia, it's 3 hours 30 mins, from Pattaya to the Cambodian border with one stop, and the same coming back, I've done it myself and the driver was quite relaxed, I'm sure if you need an extra toilet stop for 5 mins you would be fine.
If you want a visa agent to assist you In Pattaya, expect to pay between ฿30k and ฿40k for the first year, it's around ฿15k for the second and years to follow. depending on if you want a multiple entry visa or not.
the first oppo I bought I had it for 3 years, I only changed it because the internal memory was getting full, the oppo I'm using now after 1 year all is okay, it has duel SIM, very large internal memory, and also a memory card slot, which a lot of phone manufacturers seem to have stopped doing, and like someone said the camera is good, they are also very reasonably priced, I don't understand people paying stupid money for iPhones.