Ability to Edit Engagement Templates to update existing engagements in bulk

Posting on behalf of customer:

It would be great to add a feature to edit Templates that would update all the existing engagements based on that template. Customers might have several engagements on their subscription and when they need to modify these to match their UI, they require to edit the styles of each and every engagement manually. 
Instead of this, implementing an option like “Update all Engagements on this Template”, when they modify an existing template, could save them hours!