Raid - achievement Envoy armor 2
You can use one heart.
The armor set from envoy 1 is just a free asc set. Whatever you pick there has no impact on your options for legendary armor(envoy 2 will)
DPS Benchmarks, Raids, Low-mans etc.
1.) You only need a single crystalline heart, and you can use it over and over (thankfully).
2.) Envoy 1 is not in any way related to what legendary armor you will eventually craft. Envoy 1 is a completely free set of armor, use it for whatever class you want to gear up. Envoy 2 is the actual precursor. Its worth noting, you can select any stat combo with envoy 1. I personally used it to gear up a minstrel chrono (as minstrel is an expensive stat to get otherwise). You can stat swap it in the forge if you want, so if you wanted to experiment with one of the tougher to obtain combos, and then decided you didn’t like it, you could just swap it back to zerk or w/e.