Have you got a visa or an extension of stay. If its a visa just leave it as you need it for the extension. If it's an extension of stay I'd leave until after the under consideration period then you can do what you want with it, but given you will have already changed it you may as well use it for spending money
you have to mark it as funds for long term stay in Wise when you send the money but it isn't guaranteed to work. If it isn't marked correctly in your bank book or statement then you can't use it anyway unless you get a foreign funds transfer certificate. There's a FAQ on Wise regarding this. The only way to guarantee an international transfer is to use swift
you can only get that 90 day Non-O visa inside Thailand without having the required funds in a Thai bank account is if your embassy will provide an income affidavit/certificate proving you have the requisite funds. And if they will still do that you don't need the money in a Thai account for an extension either