I don't understand the obsession with MFi. This isn't an issue with MFi, but the USB-C PD specification. That's the whole point - Apple is trying to encourage a global standard for once, with the exception of the proprietary lightning connector - and anyway all the tests I've conducted are using Apple's own USB-C to lightning MFi cable, which to me is the more important point.
If both the device (iPad Pro) and the charger obey the USB-C PD specifications, then by definition there is no unnecessary risk in terms of power delivery. The circuitry on both sides will regulate the flow of power, and this has been amply demonstrated multiple times in this thread. That's the whole point of standards / specifications - MFi, incidentally, is one as well.