So, taking all this into consideration, I doubt that the Svbony 3-8 Zoom would be practical in any telescope with a binoviewer. Maybe the Svbony 3-8 Zoom binoviewed might be useful in a truss-type Dob that has had its struts shortened to accommodate binoviewers without a Barlow. Or in...
For me the difference in useability and annoyance was significant. I found the Baader 8-24 Mk IV annoying in it's lack of par focality even before I got the Svbony 3-8mm though. I would have estimated the eye relief of the Svbony at around 7-8mm even at the 3mm setting. At least...
Briefly, the SV 3-8mm that I had pre-mounted in my astrosystems low profile adapter easily comes to focus with the paracorr but as I later discovered, the zoom mechanism is below while in the adapter so I wasn't able to check the zoom functions but it did function well at 8mm while ...