No, .25mg is not too low to do anything. But I also dont think .5mg twice per week is all that high either. You will more likely than not have to fiddle around with the dosing to get e2 to the point where you feel good. This will require regular blood work and if its out of whack, adjusting the dose and repeating until youre good.
.25 vs .5? I dont know. Everyone is going to be different. Wait to see what your levels are then post what they are and that will be a start. It might be a case of using a bit higher of a dose to knock it down then lowering the dose. Of you may not be that high and .25mg would do the trick.
Myself, I cruise on 200mg--TRT (down from 250) and .25 twice per week has kept me where I need to be--even at 250. I dont use HCG though so keep that in mind.