What is the best HRT for a menopausal woman who has had endometriosis?

Patch. There is no correct answer to that question, but probably an estrogen patch will be of most benefit. And if you have a uterus, probably continuous Progesterone will be of some benefit in helping to suppress any residual endometriosis. But there are many different ways to go about this.
Depends. Even menopausal patients with symptomatic endometriosis need to have it removed before considering ht. If the endometriosis has been surgically removed , most women are able to take estrogen only ht after a hysterectomy.