I have been using the stock strap and then booster strap for years on an angle so it just just hits the liner tongue only and doesn’t interfere with the shell. As others have probably mentioned, many race boots have shells slightly trimmed to fit the strap or booster on the liner only as well.
The big advantage of hitting the liner only is that you get the tongue tight against your leg and then the ability to more easily tighten the top buckles uniformly against the liner tongue. Thick having the booster right under the top buckle would reduce the benefits.
Noticed an instant difference in precision and a more uniform flex along with never had sore shins or “boot bang” since moving to “liner only” on strap.
What mine looks like with the booster but a larger strap would be fine too as long as you minimize the hitting of the shell.
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