I have seen a lot of elk during the Oregon rifle deer season in early October when I am decked out in heavy blaze orange. The elk appear to see me about the same as they do when I am all camo in the September archery elk season. I have had a few elk in close that appeared unable to detect me motionless in the open wearing blaze orange.
I do not wear blaze during archery season because there are not firearm seasons going on. If there were forearm seasons including muzzleloaders I would seriously consider blaze.
Sometimes archers can be very convincing they are an elk. They call in a convincing manner, they show up where you expect elk to be and do not expect another hunter, they rake like a bulls antler, they use cover so they are never in the open and when they must expose they give a horizontal rather than vertical profile. They can fool elk and they can fool other hunters.
With archery techniques the hunters need to be close and in the open for shots which clearly exposes hunters to each other before an arrow is released. With a gun shots can be further out and a muzzleloader can shoot through a bit of brush. There is more room for the hunter to shoot before a really good hunter is exposed. For that reason and the fact I do not think elk can see blaze, I would consider wearing it if there was a concurrent firearm season.