Its a shame these people don't actually post facts as to whom exactly develeped this satellite, 20 Thais ? well guess they could have helped to keep the assembly area clean and that is about all.
So take a read of this
https://news.satnews.com/2022/06/21/sstls-theos-2-smallsat-ships-to-gistda-in-thailand/#:~:text=The THEOS-2 SmallSAT is based on SSTL's CARBONITE series,for early operations from SSTL.
And from another news media it was stated that it has been developed primarily by British space technology engineers as part of a Thai/British agreement