Hi Askay,
No inserts for the stagger ribs. It lets them move about more and give better grip.
Some crazy people also cut extra slots into them for more grip. They're brilliant on 2wd and pretty good for 4wd at TORCH too but lots of people are using the new cut stagger from Schumacher as a 4wd alternative.
Happy to offer advice if you want to ring the shop or come over to the Lazy gazebo on Sunday.
Assuming we're allowed to park the love bus there...?
Mark