A cylinder bore should not change dramatically during use. Open transfer ports and small bores seem to change the most. Usually the area that the ring travels is the most affected. Tend to check them over with a fine wire pick as I generally cannot see the shift on the bore wall, oddly enough 1121s are one of the small bore saws that I have found to need a close inspection. However many of the 1121s are at least on their second piston. Typically on open ports the piston will be well shaped to the bore and as such the bore should be suspect as well. Generally speaking 1129s and 1127 series are a good example of this. If you are using ring end gap to check the bore then it needs to be done st the top, middle and bottom of the ring travel on a suspect cylinder while keeping the ring gap in the same viewing position, as well the "glazed" area around transfers and such that does not come into contact with the rings and piston should be avoided while taking measurements for ring gap.
In terms of large bore closed port very seldom see one that is beyond a listed spec for ring end gap. 1122s are typically good for a couple of pistons. I have bought quite a few 395 pistons, almost never need the cylinder and if I do it has been because dents and dings.
In terms of cleaning up the scum layer to expose a fresh wall, at best the layer of scum is comprised of alum., steel, wood, oil , nickel and silcarbide or chrome. All of it needs to be smaller than the porosity and surface texture of the coating to exist and again honing will not remove it beyond the visible lines left by the hone. As well it is not an issue if the bore is in good condition.
My personal opinion is it should take a bit of effort to mess up of plated bore. I see no great advantage to honing a good bore and certainly see no disadvantage in not honing.