After the update on the London E visa application site, I've seen a report that the Embassy and consulates are specifically asking for the letter from your employer to be addressed to the embassy or consulate when applying for the METV. Somebody reported a successful E visa application but it was noted the letter wasn't specifically addressed to London
I found that the Liverpool consulate has updated it's requirement to reflect
5. A letter from the applicant’s employer (in the UK) and addressed to the Royal Thai Consulate) stating length of service and expected return to work. If you are self-employed your self-assessment form.
TLDR : Answer Summary
Recent updates from the London E visa application site indicate that the Embassy and consulates are now requiring that the employer’s letter be explicitly addressed to the Royal Thai Consulate as part of the METV application process. The Liverpool consulate has also updated its requirements to reflect that an employer's letter detailing the applicant's length of service and expected return to work is mandatory. Additionally, all visa classes, including SETV applications, now require proof of job status, income, and even pension details, following a recent update. This suggests a tightening of application rules aiming to eliminate loopholes.