Im not sure if the issue of postage will ever be resolved, however the issues of finding the trades you want to make and to account for condition (PucaTrade, Im specifically looking to you here) are becoming better and better every day
Turn 2: Glistener Elf, Reckless Charge, Assault Strobe
Dominarias legends lead heavily, only coming in behind the ever-popular Innistrad
Condescend Among the counterspells that let you invest mana in them like Logic Knot, Condescend is one that I like as it lets you scry upon resolution
Any "as [this permanent] enters the battlefield" or "[this permanent] enters the battlefield with" abilities of the exiled card will also work
Its a heavily-played card in formats where its legal, and thats mostly Vintage, Legacy, Cube, and EDH, where its a Game Changer