I only used Vercure as a 70 RDM in 4 situations:
- When healers were dead, and I needed to heal tanks and raise one of the healers. (Emergency)
- When in 4-man content and the healer simply doesn't heal the DPSes (Me and the other) even when they're at 10-15% health, and there's AoEs incoming. Happened to me a few times already, the first time we wiped. (I would call that an emergency as well)
- When doing solo content.
- When Duoing EX primals with my sister. (Pretty much the same reason as soloing for that).

So, unless you're the type of healer that keeps healing the almost full health tank instead of healing the low health DPSes, Vercure is not part of my rotation.