That's different. It's more like when HP made a personal printer, put the same internals in it that they had in there higher line printer, and then actually spent MORE money in development to make the printer slower.
The "engine" in the SL1 is the same "engine" that's in higher level cameras. It cost Canon nothing to add functionality. They chose to dumb it down, so it does not compete.
It's not always just a software limit even with the same parts.
To draw on the overclocking analogy further; the only difference between two processors may be that one runs slower. With processors though; they tend to all come off the same line and then get binned based on performance.
Direct example that may or may not be feasable: t5i shutter is the same as SL1. Both come off same assembly line; and get tested. Ones that test 'better' get put in t5i; those that aren't as perfect get put in SL1 where they're problems (one example, limited fps) are still within spec. Now; if Canons manufacturing process is good; they will have more t5i capable shutters coming off the line; so if you buy an SL1; Canon may have put a t5i capable shutter in it; and you can then use Magic Lantern to 'unlock' the extra FPS.
Or unlocking it with ML causes the camera to shake apart if it was in the original 'SL1' queue from failing t5i validation..