As I said, I called Bangkok to find out if there was a $500 limit on the option to have a check immediately deposited as was told yes. So it is not a policy that varies with different branches - at least with the Bangkok Bank. You seem to have quite a bit of knowledge so I was a bit surprised you were not aware of this.
It appears now based on what Ubonjoe posted, that any and all foreign checks will have to be sent for collection until further notice. As with a number of issues that could be important, it is best to get current information directly from the source as information you may get on forums could be incorrect and/or outdated.