Absolutely! Think about it this way -
In the states (or wherever you are from) you usually train once a day for around 2-3 hours. In Thailand, you train twice a day usually double that time (4-6 hours). So 3 months of training 6x a day back at home will equate to a maximum of 72 hours, where in Thailand it would be closer to at least double that!
Besides the quantity of training, you’ll most likely get better quality training as well. Not to mention you won’t have to worry about holding pads and if you choose a solid gym, you’ll have a pad holder working with you every session.
And on top of that, when you’re in Thailand all you have to worry about is training. Back at home, you’ve got life, work, family, relationships, and a ton of other things to worry about.
So needless to say, 3 months in Thailand will definitely improve your skills.