I've tasted the fruits from an Ichang papeda tree, and have tasted kumquat and various kumquat hybrids - calamondin, mandarinquat, and Thomasville citrangequat.
Based on that, I would imagine the rind of Ichangquat might be a little similar to mandarinquat, in terms of edibility. That is to say you could certainly eat them, but they are not really exactly as enjoyable and delicious as a Meiwa kumquat.
The rind of Ichang papeda is edible, in my opinion - interesting but maybe not the most enjoyable. It's a little like the rind of citron, noticeably easier to eat than the the rind of lemon.
I'd imagine the Ichangquats probably have some lime-like flavor as well. Thomasville citrangequat does, and to me, the Ichang papeda I tasted sort of had a flavor halfway between lime and lemon, I would say. The rind of Ichang papeda does have just a little bit of "skunkiness" and bitterness but is not really that bad (the skunkiness you would not notice unless you ate a larger amount of it).