I can answer that with a definite maybe.
I have an Ikoflex 1A 854/16 and I have the Prismatic Finder as they call it. I never actually used it very much but sometimes it comes in handy, like taking a picture through a car window where a waist level finder would be next to impossible unless you kneel on the seat. It is small, easy to install and gives an unreversed image unlike the ground glass, image brightness isn't bad at all. The bad news, not real bad, is that the image on the ground glass is 2"x2" but with the Prismatic it is 1"x1". Still very doable.
For the cost it has limited use but still worthwhile in my opinion.