Hi Priscilla,
I know it's a while back but this is my experience :
In January 2020, I went to Chiang Mai to train for two months. Sadly, COVID arrived and forced me to come home 1 week sooner. When I arrived in Chiang Mai, I visited both gyms. I arrived at Hong Thong between sessions, I guess, because it was completely empty. I didn't train there so I can't give any advice. I ended up training at Santai. It was a particularly busy time and they had 8-10 coaches. Some of them were still fighters so they would purposfully pick women to train and just do the basics. There was 1 coach who refused to train women altogether because 'Not strong enough'. instead of mentionning that to the person in charge of pairing, he would just swap with another coach and make the women feel like crap. 1 coach was completely jaded and didn't even look at us when holding the pads. There were 4 coaches I liked because they actually cared in teaching you something. Poye and Sak were my favourite. Sak mainly trained fighters. I know quite a few have left over the last two years but I don't know what the situation is right now.
Not being a fighter yet, I often felt I was put in the 'women tourists not worth training' category. My experience there was bittersweet, especially that I went to Thailand only to train.
Also, this might not be an issue at all but information worth knowing 1. Being beside a temple, women are not allowed to train in a sports tops. 2. The morning sessions were at 6am.
As for the accomodations, they varied depending on the building. One has a nice pool. The mattresses in the rooms were hard and plastic-covered, but I think that's common. Many washing machines available. Quite a few restaurants within walking distance.