Pennsylvania Tuxedo by Dogfish Head is another commercial example. It was pretty bitter as I recall. I tried a dry hop experiment where i took a smash and dryhopped some of it with spruce tips, but I think I left them in too long as I wound up with a weird grassy taste that was not pleasant
My go to for these kind of ingredients is a vodka tincture. Put couple of oz of the spruce into a jar and cover with decent vodka let sit for a week or so shaking occasionally and then add to the keg or bottling bucket to taste. I know it works for juniper, but dont have any experience with spruce. good luck.