No. The beauty of the original sustain was that it was a potent regen that healed something like 8% a tick. You only needed to cast it (which was a very fast cast and could be used like Ruin II and paired with OGCDs) and go about your business. Having physick work like a Cure spell would mean we have to spam it (unless it recovered a very large % of pet HP) and stop doing direct dmg.