Extremely viable. It was already potentially the strongest DPS setup before the hypercharge buff. Now the potency is doubled, and the duration extended 5 seconds. 10% physical buff at a 25% uptime. Also note in progression, that it can still have a 25% uptime while using resource regeneration, whereas Bards lose Foe's uptime to ballad. So They may actually need a t11 type mechanic or two in the series where magic damage is needed.