Same reroll strategy. I don't know how many epic soothsaying vests + green sparkproofs combinations I got, but I know I had 4 epic soothsaying vests + blue sparkproofs combinations before finally getting the one and final epic soothsaying vest + epic sparkproofs combination.
I forget how fast I could do a run, reroll, and start again, but I think it was something like 10 runs/hr? That definitely puts it in perspective for how much time I sunk into it. Definitely congrats to anyone who got them both, or any two specific pieces they wanted, without having to reroll over and over.