I like the idea - but it's hideous
Just saying that an easier magpul ranger type pull baseplate for the VZ58 (w/ or w/o extension), would be a great thing to have available. Personally, I prefer magpuls to the ranger plates, but putting 5.56 magpuls onto a 7.62x39 ak mag is such a pain, that i haven't tried the VZ58 mags yet... And the 308 ones are too large.
As for the extension, I see something like that being of use for 3 gun or other competitions.
You all remember the riveted 40 round mag (from two separate mags) from the Czech Republic that was shared here a year or so ago?