Thanks for the input here, everyone!
This will be done as part of some improvements to the way we handle images and assets at the start of next year. We're going to be very much re-thinking how we approach digital asset management.
As part of this we're going to allow you to have a library of images and assets that can be embedded in text fields, and also re-used across your projects. Makes sense!
We'll update you all here once we're ready to do some testing.