When I first saw the Cage of Changes in RoP:M, my first thought was, "I can design one much better than that!" I had some build points left over during covenant creation and created this seemingly simple monstrosity:
Trough of Alteration
Base 5, +1 Touch, +5 for 24 uses/day,
A small food/water trough which inflicts 1 warping point (see RoP:M 79) each time a creature eats food or drinks water placed inside it. On one side are several orifices in which you can place Vis, which fuels the device in unclear ways. It was the maker's hope that the vis would affect the nature of the warping, as part of his research in breaking the Lesser Limit of Warping, but he decided to trade it for a very nice wolf-hound before coming to any conclusions.
The Trough generates up to 24 points of warping/day across a herd of domesticated animals. Which doesn't seem so bad, until you notice that over 8 seasons this is (2 years * 365 days * 24 uses =) 17,520 points of warping, which could be around 233 creatures warped to Lvl 5. From a 3rd Magnitude device.
With the sections on Magical Menagerie in Projects, and apparently another section on kennels in Lords of Men, I can figure out how much it costs to keep this horrific operation running. Finding enough animals to feed to the beastly thing might be another problem.
And then there's the question of how to determine its effects -- meaning both:
how does the SG decide what those 233 transformed animals look like, and
how does my magus determine which virtues and flaws each beast has received?
"Effects of Warping" on p. 168 says that the Minor Flaw you get at Warping Score 1 should reflect the predominant source of the Warping Points. In this case, since most (if not all) of the WP come from the trough, I'd say they all gain the Obese Flaw.
The second Minor Flaw at WS 3 could be Greedy.
For the mystical Minor Virtue gained at WS 5, possibly a stick-less variant of Dowsing that enables the warped animal to find some kind of foodstuff or other item according to his nature. Pigs could find truffles, cats could find mice or birds, dogs could find bones (which could be expanded to anything Animal or Corpus).
But I don't think the crafting magus has any control over what Flaws/Virtues are granted with the Warping.
(I saw this and first thing I thought of was a maga with an enchanted ruler with this effect.)
Well, but they wouldn't ALL gain the same Virtue and Flaws, would they? Else the concept in Cage of Changes wouldn't happen, of hoping to produce an animal that gains the Form Monstrosity flaw, or begins to accumulate Muto vis.
Perhaps the Obese/Greedy/Dowser is the most common manifestation? That would certainly make sense. He's starting with chickens and goats, so I doubt they'd Dowse anything useful at first. Most of them would get consigned to the kitchens....which makes me wonder how Warped meat tastes.
Still, it'd all be worth it for the Terram Monstrosity Chicken's eggs. Or the fire-breathing goat.
Oh, of course he doesn't -- Lesser Limit of Warping. The option to pour vis into the device is purely an rp-flavor sort of thing for a researcher trying to achieve a Breakthrough.
The question I asked about the magus was how does he perceive or identify the effects of Warping on his test subjects?
Well, InVi and InAn are both useful for studying animals and magic, and can certainly identify Might, Form and other such things. I think that a lens or window could certainly be enchanted to reveal minor information (degree of warping, Form if acquired) but that learning more (unless it's bloody obvious, like fire breath or stone skin) should be a laboratory activity. One which, I reckon, should certainly provide Breakthrough or Insight points, though perhaps multiple warped critters might be required, or different types of warping to acrue multiple insight points.