Okay, I'm not an expert, but I could find this. (By the way, sorry, I had misread Entrace for Estrace.)
-The product you mentioned, entrace. It does not exist, from the looks of it. See for yourself: Wikipedia and Google are silent on the very existence of such a thing.
-You might mean estrone, which is an oestrogen with much weaker properties than estradiol, and the primary oestrogen in post-menopausal. I don't have the details, but I think when there's an excess of estradiol, it can be converted to estrone, and vice versa (though the former happens much more often). Once it's estrone, it can in turn be converted into estrone sulfate, which stays in the body for a long time. Then it can act as a sort of storage: estrone sulfate is converted to estradiol if it's lacking.
And of course, like with pretty much every product in excess in the blood, excess estradiol can most probably be excreted through urine.
So uhm... I'm not sure why he literally doesn't care about estradiol levels. It is true that testosterone can block the effects of estradiol (hence why most FTMs just take testosterone, period), but still... Your T levels are mainly dependent upon your T blocker, whilst your E levels rely on the actual E you take. It doesn't make much sense to me to just ignore it.
Going by that logic, you'd give someone just T blockers and expect breasts to grow. :x
I'm not sure I understand them, really. Of course, if T is still not under control, the E level is not all that important, but once T is low, I'm pretty sure the E level is a very important information...
You should really ask your endo directly. Therapists, no matter how experienced, aren't hormone experts, after all.