There are so many other areas of your endocrine system that a defunct thyroid affects though, especially for a woman and all the hormonal level spikes. I still don't have the energy or abilities I had before my diagnosis, even though my T dosages are supposedly correct.
I have doubled up on my T3 out of curiosity before for a few days and my metabolism and fat loss was through the roof. But if you do it too long, your body will stop producing its own T3.
If you get some T3 from your cousins in India, be prepared for premature balding.