While I have absolutely no experience with the specific device to which you refer, my past experience with similar schemes indicates that the idea is not a good one.
Devices like this are suitable only for people who are permitted to own only one serialized gun part (frame, receiver, etc.). In such a case, you would want to add a conversion kit of the highest quality, but I have never seen a high-quality conversion-to-carbine kit for the M1911 frame.
An old-line Los Angeles gunshop used to make a M1911 conversion that used the pistol frame and a rigidly-attached, single-shot, barrel-and-receiver arrangement that would handle anything up to .308 and .30-'06, but very few of them sold, and they were discontinued.
If you have a dream of instantly converting back and forth, pistol to carbine, forget it. Sufficient parts have to be switched, for which tools will be required, that the conversion is anything but "instant."
Then there's the accuracy question. The kits I've seen use the M1911's slide, and the pistol sights upon it. The greatest advantage of a pistol-caliber carbine is its much longer sight radius, which makes the carbine a good deal more accurate than a pistol. But if the conversion uses the pistol's original sight radius, there really is very little advantage to be gained from switching.
It's most likely a very bad idea.