A general reply to some of the various comments received:
Them's my Sunday-go-to-meetin' Crocs ... thankyouverymuch ...
I'm lovin' a really great suggestion of putting a prusik loop in between the CMI and the 'biner so the load can be released without backing out the cams ... great improvement, IMO!
Yeah, I'm thinking' the "Rope Jack" is just for light loads! It ain't gonna replace my Maasdam - fo sho. The 'hope' will be to use the "Rope Jack" to remove slack & stretch and maybe to lift light loads without having to break out the big guns.
Cams, even 'untoothed' like a Rescucender and Gibbs, have been shown to shred a rope with high loading. There are much better tools for the heavy work.
The short handle gives a leverage of roughly 5:1 ... I figure the max. I can apply with one hand will be a safe limit for the ascender and to keep from shredding the rope.
One important note about that handle: The handle in the vid is a section of a good quality hickory axe handle ... worked OK. First attempt was with a 1X2 pine board ... it BROKE - I went a**-over-teacup ... sorry no vid of that.