Thanks for your interest in this issue.
Unfortunately, this suggestion isn't currently on our roadmap - we’re instead focusing on bringing you a new search experience, and are investigating improvements to permissions.
We do though understand the value that common variables in Blueprints would bring - we'll typically review this request at least once a year, at which point we’ll consider whether we need to alter its status.
There is an add-on available in our Marketplace which provides a solution to this problem - Blueprint Creator. I’m aware this isn’t optimal, but wanted to draw your attention to the workaround nonetheless.
I apologise for the disappointment and will ensure we provide you with an update on this feature request within the next 12 months.
Jenny Millman | Product Manager - Confluence Server