I have checked with TESL Gold Star TEFL Recruitment and got a reply from them.
Two things are noteworthy:

1. They said that they currently have no job offers from public schools (I asked for it), and they currently only offer positions at EF and some (rubbish?) kindergartens (EF is known for what it is - a useless English language mill franchise chain with no professionalism, many hours to work yourself to death and a very low salary; so do not even consider to work for them; in addition, their reputation is really bad in the ESL industry, and listing them on your resume/CV as one of the places you have worked for may bring you more harm than do any god).

2. The other thing about that agency is that they ask you to submit sample lesson plans in addition to your other documents to see whether you possess the essential teaching skills. I am really wondering what kind of job applicants they must have been dealing with in the past that they feel it necessary to ask for sample lesson plans. Obviously, it must have been these kind of losers from the West like Mr. Pitbull from Suzhou city at a certain foreign language pretend "school" there who are highly uneducated and unprofessional with mental personality disorder and therefore would typically work for absolutely rubbish places like EF as they would have nowhere else to go.

Very enlightening!