@Graham ******
No. They don't even accept Lao documents in Laos, only English and Thai.
Thai staff at embassies abroad can usually understand only Thai and English, not the language of the country they're located in as they move around a lot, as diplomatic staff do.
While some staff may be able to understand whatever the local language is, or they may hire locals from that country for certain positions, generally the policy is to only accept documents in Thai and English.