Q.Buttercup and Butternut squash are doing fine now in my garden, I’ve planted these for 5 years now with fair to good results here
in northern Mn. People say I should thin out the blossoms to produce more squash that mature to harvest.
When do you thin out the blossoms?
Thin male and female?
How many do you thin, what %, I’ve a lot of people recommend thinning blossoms, but none have answers to above questions.

Certified GKH Gardening Expert
There are more male than female blossoms so if you're going to thin, pick the males. They can be dipped in batter and fried, too! That is the only reference I see to removing blossoms.
https://www.gardeningknowhow.com/edible/vegetables/squash/female-male-squash-blossoms.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/growing-butternut-squash.htm
https://www.gardeningknowhow.com/edible/vegetables/squash/squash-blossoms-falling-off-vine.htm