Yes,Mr Ettin,they cut.
A basic sear jig can be had from Brownells for about $25.00
I went for the Marvel,myself. I don't think most folks can feel/maintain the flat of a sear engagement surface on a stone.
I suspect cold bluing the surface before stoning would be enlightening.
In my trade/profession,opinion did not cut it. That's why toolmaking,machining,etc has measuring tools/metrology. For my home use,thats why I recently bought a Browne and Sharpe toolmakers microscope.
30X,protractor head,crosshair reticle,and X-Y micrometer heads about 1 1/2 in in dia,direct reading .0001. Nice tool. I can tell you if the Arkansas stone took off .0002. I can also tell you if its square,or rounded.I can measure the primary and secondary sear angles,and measure the lengths.
If you don't measure,you don't know.
I use a sear jig.I never went to Trinidad Gunsmith school,but I suspect they teach "Use a sear jig"
As a kid I kept my Buck folding Hunter pretty sharp with nothing but a hard Arkansas stone. The stone does cut.