you are thinking regardless of your previous history then nothing to talk with you.U dont know anything about Thailand Immigration then.According to my 15 years experiences(used many type of visas)change passport and enter from suvarnabhumi.No need to go Laos(if u go just for enter thailand).Use agent.Next time make proper visafor staying long term.Otherwise she or he will be denied with red stamp.Good luck to him or her
I can recommend you change passport first and pay money 8500 baht for agency and enter to Thailand from Suvarnabhumi.Because u stayed very very long time In Thailand in One time.
this is good point but your visa extension every 3 months or 1 time 1 year ED?which one?There are many type of ED?What kind of do you have?And are u sure u are going to lessons?And another question this will be your last extension or not?(i mean last 3months)