Huh. That and giving Pepsis charges definitely would be more useful/interesting. Never thought of that.
To OP:
Really though, I normally use it if a Eukrasian Prognosis leaves 2+ people still under 100% health (which is fairly rare). It's an OGCD that doesn't need resources so I just pop it.
I agree it's not an amazing ability and could use see some improvements (e.g. it heals for the maximum shield value instead of current, that way the "ideal" way of using it would be popping it right before shields break), but definitely not "useless."