The cut outs on the early HS22s were done by Pace themselves, I think Magura did them for the next gen yellow ones. You’ll see that the cut out is silver rather than the factory black.
Most good machine shops could do it for you or there is a very good engineer on here (Elite504) who did mine and may be able to help (at a price, expertise doesn't come for free).
Most good machine shops could do it for you or there is a very good engineer on here (Elite504) who did mine and may be able to help (at a price, expertise doesn't come for free).