How to apply a Behaviour to a large set of projects?

[Yves Martin]

 Hello

Our system is large - 720 projects - and I am interested in a way to apply a behaviour - or even better a group of behaviours - to a group of projects.

I cannot afford to add project one-by-one in Behaviour Mappings.

Is there already a way to do it? If not available as UI, maybe thanks to an API I may call?

I fear Script Runner may have difficulty to "scale" when testing against a large set of projects. Would it be recommended to inject Behaviours as a JIRA plugin?

Thank you in advance for your help