i'm not sure about this, but The some language school said that they need to send your application to the Ministry of Education and it takes about 2 weeks to get your application back and then they need to go to the immigration for convert your current visa to your education visa. So it's might be possible.
i recommended you should contact to the language school asap for they check your passport and tell exactly details to you.
(My boyfriend start this process on 3rd July, Next week he might get ED visa i guess)
Hi! has your boyfriend successfully gotten his ED conversion through insight without having to leave the country?
Getting an ED visa during tourist visa amnesty
in Thai Visas, Residency, and Work Permits
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Hi! has your boyfriend successfully gotten his ED conversion through insight without having to leave the country?