I wrote a guide to building and playing UR Delver if you guys wanna check it out: http://sylvanstudies.com/2017/11/01/vintage-ur-aggro/
Also have you guys tried Chart a Course? By no means is it a deck breaking card, but it’s honestly not bad, and it helps solve some issues we have late game. I feel like it’s worth trying in some builds, especially Aggro focused ones.
I have been playing Chart in my Legacy UR Delver build. It's pretty good. I haven't tested yet in Vintage (in fact I have barely played any vintage for the past couple of months). One guy I know says it's very good and has 4 in his build.