Hi Pluton, The range whould be 20x-60x. The original pentax zoom it an 8-24mm, same as the Baader and the range is 20x-60x, so that is one question out of the way. This Mk IV versión has been optimized to reach focus on this type of spotters, minimizing the distance from the zoom to the scope mount. The problem with Pentax scopes is that the bottom of the mount features an stop notch, that fits the Pentax eyepieces, but prevents some eyepieces to sit completely in there.. This can be easily fixed with a small cut, to the bottom of the astro barrel about 3 squared mm, in the event that this would be the case. The other possible problem it's the tightening ring of the Pentax mount lifting the eyepiece when secured in place. This happened to me with the PF65. When i inserted an eyepiece in the mount, İt sat flush on the mount, but when the ring was closed to secure the eyepiece, the motion lifted the eyepiece a few mm, and it was no way to push it down. If the eyepiece was too close to the focal point, then this could be a problem.
I don't know if those problems actually affect the Baader Mk IV, but those are the design features of Pentax scopes that prevented some eyepieces to focus when i owned the Pentax.