A flickerfixer is allways a scandoubler too. The technical prerequisite to remove the flicker is scandoubling the image first then cache every singel image and send it out twice thus doubling the refreshrate.
Problem with all the A2000 scandoubler /Flickerfixers is that they are only 16bit so if you put it into an A4000 you will miss out some colors sice AGA is 24bit.
