What is the process for renewing a British passport in Thailand and can you keep your old passport?

Hi all.

Seeking some advice from anyone who has renewed their British passport recently in Thailand.

I'm aware of the official British website and done a little reading but really want to know specifics about the following questions:

1.

I believe from memory that they like to take your old passport away when you renew. My concern here is that I have my current visa stamp until July and other stamps Immigration might want to see like original entry etc. Does anyone know if we can insist on keeping it I'm not happy with the idea of just making photocopies given how Immigration works. I have thought about just declaring it as lost to avoid having to part with it. I also have sentimental reasons 🙏🏼

2.

How long does it take to get the passport? I'm thinking of traveling to Bangkok (I know you have to have an appointment) and was hoping that you can pick it up within a couple of days but I may be way out in terms of how long it takes?

If it takes some time is it possible to pay for it to be sent to your home address via secure post? Obviously I want to avoid having to drive 6 hours or more back to Bangkok just to pick it up if it's not ready within a couple of days. From what I saw online it indicated it could be 3 weeks from appointment application date.

Any advice and information concerning what actually happens much appreciated 🙏🏼

UPDATE:

What a complete farce. I've been checking the UK government website and they have come up with this gem for providing evidence of your Thai address, pretty much all of it is impossible. It mentions your visa, well my original visa was when I arrived from the UK 2023 so UK address and since visa extension stamps again no proof of your address! Just what do they want? Everything sensible like bank statements or rental contract or even bills in my name isn't even mentioned 🤬...do these clowns 🤡 actually understand what they are doing and asking for? 🤔 They mention a resident 'permit' do they mean a residence certificate? That I can get albeit a visit to Immigration and 500 baht.

Can someone who's done it and been to VFS Global confirm what will be accepted despite what it states on the British government website. Your help much appreciated 🙏🏼

Afterthought...is a TM30 acceptable? Everything is in Thai and English except for the document title so it would still need to be translated 🙄

FURTHER UPDATE

After a lot more digging and research many people have said a bank statement in English is acceptable and also the TM30 so I'll prepare both and hope for the best. My Thai driving licence would have also been okay but it's got the last address so I'll try and get that updated before I go as a back up 🙏🏼