What ever happened to angle milling cylinder heads?

I had a set of 440 source heads angle milled .040 from the spark plug side to bring an 8.2:1 440 up to 9.5ish :1. I think if you go much over .050-.060 the intake manifold will need to be corrected on a mill. Both shops I have worked with here in OR will angle mill however they said no cbn cutter for some reason (aka no MLS gaskets).

Angle milling is a viable option in some cases.