I decided to attempt the FKT on Mailbox Peak (using the new route to go up and down) on 8/24 since I'm traveling in the area! The trail is actually really runnable up until the steep boulder field toward the top! It is also pretty wide in most places and not very technical, lending itself to faster running. I made it up to the mailbox in 1:28:10, and back down to the gate with a total time of 2:18:22. Carried 500 mL of water with me and maybe drank 2 sips the whole time. I had a Spring energy gel that I carried toward the top. The views up there were so great that I wanted to stay up there for longer, but instead snapped a couple pictures and turned around for the descent.
new trail, gate-to-gate
2h 18m 22s