I think it's natural to be scared and un-sure about bottom surgery when you start out, especially when you have working male genitalia. But in my experience, HRT is equal to chemical castration. If you stay on it, you shrink down there, and eventually the erections go away. You may want to research what happens after someone has an orchie (if you're not looking for GRS) to see if that's what you want, because without testosterone, penetration might be a little difficult.