Update: with a combination of tweezers, brute force and sheer rage I did manage to get one of the grooms through the hole.
As predicted it fits nicely when it is in there. But I had to do it without the cage fitted, and once you get past one or two groms it would be impossible to get access to fit the others. Plus if I ever need to remove the cage for maintenance (and we all know that is going to happen right?) it would be a nightmare.
I think the way forward is to cut a thin channel into the existing drill holes and create my own “slotted” fitting. That does risk weakening the frame, but would give me access to fit the groms and remove them easily for maintenance. If I do screw up the frame they are cheap enough to replace.
Or of course I could just write off the $6 I spent on the new camera cage, go back to the old one and live with the jello. Surely it can only be a matter of time before they release an upgraded Femto frame to take the new cage? But I’ve started, so…
I’m going to sleep on it!