If there is a DTA in place between your country and Thailand, this will be the rules that apply under "Permanent establishment". Typically, they will need to prove you have a "fixed base". I'll be staying in an Airbnb when I do my work which is hardly a "fixed base".
Just make sure the company doesn't pay for your expenses in Thailand or gets involved. etc paying accommodation, flights. It needs to be clear that it is funded and organized on your own personal expense. and that the company did not require you to be in thailand to do the work.
I found this section for another country (Canada) that describes about PE:
https://djb.com/2022/08/home-office-and-permanent-establishment-for-non-resident-corporations/
The rules are similar for Thailand and any other country.
Non-resident corporations may not be considered to have a permanent establishment in Canada in the following situations:
1. Non-resident corporations do not bear any costs relating to the Canadian employees’ home offices in Canada;
2. Non-resident corporations do not use the Canadian employees’ home offices for any advertisement, business address, or on their website and,
3. Non-resident corporations provide an office space or hoteling work arrangements in the non-resident corporation’s principal jurisdiction (e.g., the US) to conduct their official duties. The employees may choose to work from their home offices in Canada.