My Rossi boots were giving me major shin bang and I took them to Surefoot here in town. The boots were to lose around my shins and I couldn't tighten them any more. To solve this I got some neoprene inserts attaches to the liner between the shell to take up some space and a booster strap.
The booster strap was xplained to me as similar to my standard strap on my boots, but better because the standard strap uses velcro and when pressure is exerted on the strap the velcro spreads, loosening the strap. When the pressure is released the strap does not tighten back up to its original position. I swapped to the Booster strap and I can now get my boots so tight I can cut off blood flow to my foot.
I am still trying to find the perfect balance on the strap and buckles on my boots, but my shin bang is noticeably going away.
Hope that helps.