so please make me understand. As im really confused.
It mean that you can not exit Thailand for 3 years ?
Say you have extension of stay based on marriage then you travel to Europe and then you entry again in Thailand it means that every time you travel outside Thailand you bring the clock back to 0 ?
i know a guy who was overstay 1day on a 1year visa issued in Malaysia got stop by police on that visa run day and got 1 month in jail and 5 years banned from Thailand .
then me i cant help you with advice . But you can give the answer after you cross :) go there and exit Thailand then explain to Cambodian officer that you want to entry on french pass then i think will be no issue .