Well I just purchased a Chromega head (used, cheap, allegedly good condition) and hope it arrives soon. But it doesn't have the extender mounting kit. I'm hoping I can "McGyver" something with the existing brackets and longer tubing, otherwise mounting it is going to get expensive.
It seems to me that the filter size for the condenser head is 4-1/2 inches diameter (but probably a 6in square mount). I have an extensive set of color printing filters that are mounted in 4 inch mounts but the filters themselves are only 3-1/2 inches or so. I wonder what would happen if in mounted them to larger mounts. There may be less light at the edges, but the enlarger bulb is itself rather a point source (it's not 4-1/2 in wide itself) and it might not matter, at least for 35mm and MF (6x6 and 6x9, I don't have a 4x5 camera yet). I may give it a try, it would be interesting to see how a color print would look printed with a condenser light source.