Hi,
I am able to restrict the maximum number of items in the measure feeds by using "max" in the feed definition. I noticed that dimension feeds require "maxStackedDims" instead of "max" to restrict.
I have modified the Bullet Chart extension's flow.js. I'm using Lumira 1.30 as well.
Here are screenshots of my flow.js and the corresponding Lumira feeding panel. As you can see, the "+" buttons disappear after I reach the limit.
Hope this helps!
Regards,
Maaz.