I used an Agfa Colormat 1961-1965. (I am not sure if your model is the same - it's along time ago) They are amazing enlargers. From memory you cannot use them for B&W, as exposures can only be made through the additive system.

The control box is to set the machine to give the right colour, but this needs to be reset every time you start a new box of colour paper. This is not a problem for photofinishing labs as they will have bought maybe 100 boxes of the same batch. An amateur might buy one box of colour paper only, so setting up the machine seems hardly worthwhile. The many controls on the box are necessary to adjust "slope control" or in other words ensure the correct exposure and colour balance remains the same on under-exposed negatives and over exposed negatives as well as normal negatives. The masking frame houses a photomultiplier tube to measure the light passing through the paper.

They were originally for Agfa unmasked negatives, but can be used with masked negative.

Amateur enlargers made 40 years after this are toys compared to the Colormat. Fantasic engineering for the time.