Well, I'm kinda having the same issue about greasy sunscreen. Even after waiting 15 mins, my face is oily AF, but my neck looks normal. After reading about using oil blotting sheets or tissues to great rid of the grease, I've reached a conclusion.

Use a bit more than 1/4 tsp on your face, wait 15-20 mins, then use a good translucent powder to help absorb the oil, next use some oil blotting sheets to lightly press on the face to remove the grease. You can top with some more powder for reassurance. With oil blotting sheets, I think they don't remove as much product as tissues. Anyways, if you started off with a bit more than 1/4tsp, I doubt you'll take so much product off that you'd end up with less than 1/4tsp on your face. That in addition to wearing hats and sunglasses, and being careful about sun exposure in your everyday life. I think it's not that bad. Most people don't reapply sunscreen when using makeup, not everyone is perfect. I'm just using this way until my asian sunscreens come. Shipping to Canada is a pain. Hope this helps someone.

I don't recommend using this method long term, but no one likes to waste money on sunscreen they can't return. This might be good for people on strict budgets that can't buy another sunscreen for awhile. If anyone found anything wrong with anything I said, please correct me!