You should be fine, I made a little portfolio on canva, showing images of what I do, as well as screen grabs of incoming payments and monthly takings etc.
and I wrote a cover letter myself, explaining my business and clearly stating I wouldn’t conduct my business in person in Thailand, or with Thai customers in Thailand. I think they like it if you reiterate that you’re not going to do anything they don’t want you to do there. London embassy was super quick and easy to deal with for me
basically because I don’t really intend on doing cooking classes or Muay Thai, but if this application does fail- then I’ll probably re apply with the soft power option