As mentioned, 50 END, rest SPR and full END are the stock support-builds. END makes sure you don't die as fast with the increase in Defense, HP and block rate. The SPR gives you a little more functional SP.
Skill enpowerments are the kicker. Full empowerment of Heal Power,CD and SP consumption. Optional empowerment for Invincible Duration up to 5, though it's usually nice. Make sure you have some points for the first AoE heal, Recover. Suggested a few points in CD.
Consider adding points into Bash power. Though you mentioned it's a Pure Support build, you might want to hit something once in a while. See if you think points in Quicken's CD will benefit you. I personally didn't use it enough to think it mattered but full empowerment in CD takes 1min 12 seconds off the 4 minute cool-down.
It's no bother
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