Of course my initial Comment is relevant because it is pertinent information that Hong Kong is NOT a part of China for Mainland China immigration and transit purposes, and Hong Kong is NOT a part of China's Visa–Free Transit Policy
Therefore, you would be making a direct entry into China at Beijing, as Hong Kong is NOT 1 of the 60 Ports of Entry China has specified for their 10-Day Visa-Free Transit Policy
However, one can easily use the SRT Long Distance Trains from Krungthep Apiwat Central Station at Bang Sue to Vientiane (Khamsavath) Station for easy entry into Vientiane, Laos from directly from Bangkok using a Lao Visa on Arrival (Lao VoA) Sticker which is USD $40 and cheaper than a Lao eVisa at USD $55+ , but the Lao eVisa Sticker is smaller than the regular Lao Visa Sticker which takes up a whole passport page
Unrelated to a Thai DTV Visa, Thai Visas in general, or Thai immigration, if you want to catch a Thai international bus (บขส) that crosses from Thailand into Laos (particularly the Udon Thani–Vientiane บขส buses), then you need a Lao Visa Sticker beforehand as the บขส Thai buses will NOT wait for those that are getting a Lao Visa on Arrival (Lao VoA) or even have a Lao eVisa (only those with a Lao Visa Sticker issued by a Lao Embassy/Consulate)
only 8 land borders and 8 sea ports (yachts and cruise ships) suspended the use of the Paper TM.6 Arrival Card since 15 April 2024, but starting 01 May 2025, ALL of Thailand's borders will start using the TDAC Digital Arrival website
Yes, for someone holding an Expired Thai Passport and making a direct trip to return back to Thailand, it is up to the airline to allow boarding or not, but on arrival in Thailand, a Thai Immigration Officer will stamp the following:
Up to you, but directly from the Thai Embassy in London website in the English language version:
"...
1.) All applicants must be residing within the UK/Ireland/UK territories when apply for the Visa. The Royal Thai Embassy has the right to cancel the visa applications should you fail to provide the evidence of your presence within the UK/Ireland/UK territories while applying for the visa.
...
2.) The Royal Thai Embassy, London reserves the right to request additional documents / interview in person at the Royal Thai Embassy, London, and amend visa categories as deemed necessary as well as reject any application without prejudice.
...
3.) The applicants must provide genuine documents and information. If the applicants are found to provide false documents or give false information, their applications will be rejected and be reported for further determination of appropriate action and future prohibition to enter the Kingdom of Thailand.
Well, what country's passport specifically are we discussing about?
Generally, many people from nearly all countries have lived and are living in various countries around the world for decades, some continuously moving and have been able to renew their passport at their own country's embassy/consulate for decades without problems at different locations, so dunno what this inquiry about passport "status" is all about???