I have seen posts where the issue has been brought up before, but never in a dedicated post.
So i dedicate this post to the one specific problem.

Boards get heavy with time. Miro is a blessing in my line of work, but gets bogged down quickly with many users who add photos and references willy nilly. 

We need a system where a set of standards can be implemented to keep the load times down.

As an example: From the get-go, say that everything that has a width over 1920px gets proportionally scaled to that. And everything that has a lower resolution gets left alone. 

Or one could mak rules on the width of an image. Whoever uploads will have the images rescaled to fit a chosen rule. If you upload a picture that is 2048 wide, you could get the option to leave as is, or scale image proportionally by making the width 512px, 1024px, 1920px or some predefined value set by the boards owner. 

Or this could be done after the fact, and all selected images, could keep their size on the board, but be reduced in actual size by a percentage. I imagine the workflow being that you select the images that slow your board down, and you set rez to 20% of what original images were. They all stay the same size on the board, but are actually scaled to save space.

Another way of making the images easier on Miro is to have a system that identifies the largest files. Then something can be done about them manually.