Is there a minimum time requirement for holding the £11,000 financial evidence for a Thai visa application in London?

Depends on the embassy I think. I got my DTV from the Thai embassy in Tokyo. Because my bank statement was all in Japanese, I had to get my Japanese bank to make me a bank balance document in English. The bank made me a document that stated my current balance, but it didn't state how long the money had been in the account, it just showed the current balance on that day. Though I'd had the money in the account for well over 3 months, in theory, I could have deposited the money on that day. But that could just be the case for people applying from Japan. From reading many posts from other people in this group, it seems that some country's embassies want you to prove that the money has been in your account for 3 months

I moved the money an hour before applying, approved.

Embassy dependant. Check the website of the embassy you’re applying at.

I contacted the embassy beforehand and was told it only need to have that balance on the statement date, visa approved.

I moved the money about 2 weeks before I applied and was fine

I placed the money only for a few days and got approved.

I was told by my agent whole 3 months showing 0 baht ,

London has no seasoning requirement.

Search in this group and the answer is there.