Yes, estradiol hemihydrate is much easier to take sublingually because it'll dissolve a lot faster. Although both of them are safe to use unlike the older synthetic estrogens that you'd find in birth control pills.
By weaker it's just weaker per mg. It's not like one type is better for your hair since it's still going to be converted into estradiol in the body, but with the hemihydrate you'll get better e2 levels at the same dose.
Just make sure to take the quarters evenly spaced out so you don't get mood swings, hot flashes, etc from your e2 levels spiking and then dropping too low. (check the attached picture) Might be a good idea to up your dose to 4mg daily if you feel worse in between your doses or if you'll be taking estradiol long term.
Happy holidays to you too.
That looks like decent regrowth. How many months apart are the first and 3rd pictures?