Hi, here is my passport history :

- 1 month entry (I discovered Thailand!)

- 1 month after : 2 months entry+1month extension

- 1 month after : 2 months entry

- 1 month after : 2 months entry+1month extension

- 1 week after : no visa : 1 month entry by air (and actualy in Th)

Do you think, if again, after this month, I go outside and come back by air, for sure, I will have again 1 month entry?

Is there a moment they'll say "oh, stop, you came too much, too much visas, too much entry", or "Ok we accept you for a month, but last time" ?

Should I change passport to "hide" all these visas, extensions, entries ?

Thanks again

No, you should be able to get the 30 day stamps for air arrivals indefinitely.

However, there MAY be issues with the airlines boarding. Perhaps people doing this currently can speak to this. I remember being hassled boarding a RT to Malaysia being asked for my eventual ticket OUT of Thailand, but a long time ago.

at this moment in time there is no limit on arrival by air, 30days.

Some Thai Embassies in the region apply stricter rule for issuing back to back Tourist Visa.

Otherwise there are many other ways to stay in Thailand.

ED-Visa for study, retire if over 50years of age, Non O if married, Non B if working.

To the OP:

I am using these combinations of tourist visas and exempt 30 days stamps on arrival for the last 11 years, since I decided to spend most of my time in Thailand...

And, knock on wood, I never faced any trouble...