I tested out Drain Bolt after the revamp. The damage increase still does not quite make it is strong as a well teched Prime Bolt but it now seems to have the sort of force + Life Stealing to do more of what it is intended to. With Breeze running and the Winds cast on the Golem I was able to keep my health up just fine with Drain Bolt VI vs. a Jade Golem and Zarla is not even a Primalist so in Tsume's claws it should be pretty solid now.

So to make a long story short, Thank you to the Devs for looking into that and I believe the upgrade has fixed Drain Bolt and made it worthwhile again.