Open vs. Closed Valley on steep roof

I’m getting ready to reroof my old farm house that has about a 12/12 roof. It presently has open valleys that appear to be bent at 90 degrees. In this sharp of a valley can I use a closed cut or woven method? What would your prferance be in this situation?

Open valley, w crimp, 20oz copper.( my preference )

anyway you like.
it just dont matter if its 90, 45, 65, 75, 20.

i like dennis’s idea. but weaving the shingles if the are dims i dont think are approved by manufactures. Dont quote me on that have not picked up the latest installation book this year yet. i would go what with dennis is saying. I care what my roofs look like and perform. i just dont do whatever and call it a day.