I'm also finding it tough finding Beetleweight events. I contacted Robots Live and it's true they do run an arena, but it's limited for pit space so pure Beetleweight teams are kind of left out in the cold.

Also Kinematic have put their championship back to February now based on their Facebook posts.

I guess that it's not popular as a weight category in its own right but seems to be most popular as a side event for roboteers in Feather and Heavy events