8 hours is a really long time, especially since some keys don’t get finished.
I would like to see the portal cooldown be reset when a mythic keystone is started, rather than finished - this way you can use your portal to next dungeon if group can’t finish the current one.
Additionally, since these portals are about to be account wide, i think the cooldown should be reduced. These portals are very handy - horde alts can use waycrest manor portal to get to Kul Tiras (without questing in BFA - which really no one wants to do for every alt they want to bring over to Kul’Tiras).
People can use their Necrotic Wake portal to go back to Bastion and farm that mount, etc. The Mechagon Keystone hero portal brings your character directly to mechagon, which can be a long flight for alliance or a real pain to unlock via questing for horde.
I just think it would be a nice quality of life to make these two changes:
- Cooldown of portal reset when keystone started
- Cooldown as a whole reduced, maybe to like 4 hours?