It's definitely useful at times. A cheaper alternative to Fortitue for mid-game healing when rotating between camps/lanes/fights, as it similarly provides a burst of heal between any action allowing you to avoid having to go base for a full heal.
Also useful if laning with someone who refuses to stop diving when they're at less than half health... Definitely mitigated how much a lane-mate feeds by popping it on them whenever possible.
On Yamato I've been preferring Restorative Shot and Enduring Spirit. The latter is especially nice as you get 10% spirit lifesteal super early. Huge on spirit heavy hitters like her.