Hi Festoolviking, Seth and Everyone,
The combination of a Kapex and either a Mini or Midi dedicated dust extractor makes good sense because sawing does not create a huge amount of dust.
Personally I use CT22 with several of the Kapex in my shop, but I started with the CT22 before I owned a Kapex. One advantage of the Mini or Midi is the hose enters from the top so it is a more direct path and kinks less.
The Kapex will accept a 36mm hose as easily as a 27mm hose, but it is not designed to work with a 50mm hose. To do so you would need an adapter fitting, which will interfere with operation of the Kapex. In point of fact, the 36mm hose provides all the suction the Kapex can effectively use.
I made it a policy to only use AS hose in my shop long ago. With a short 36mm hose for the Kapex the non-AS hose will work.
Because I own more than one Kapex and I need a slightly longer hose because of the CT22, what I do is purchase 36mmAS x 7m hose, plus 2 each vac and tool ends. I start off by cutting 2.3m off one end, then fit both pieces with the appropriate fitting. I have the right length hose for the Kapex and a useful 4.7m hose for other tools. Then when I need another Kapex hose I cut the 4.7m hose in half, and attach the appropriate fittings. This leaves me a third Kapex hose. Best of all the fittings do not wear out, the the next time I buy another 36mmAS x 7m hose and no extra fittings.
With a Mini or Midi half of a 3.5m hose is long enough.
For the 2 Kapex permanently installed in my shop, in addition to the 36mmAS hose attached to the dust port, I also have a conventional miter saw dust shroud behind and below the Kapex connected to my plant dust collection system. That deals with the small amount of debris escaping the Kapex dust collection. When we use a Kapex on a job site we place the UG stand on a drop cloth, then clean the drop cloth using the CT as needed.