1. As canon as you want them to be! We play that part by ear. You can retcon stuff if you'd like!

2. It has indeed been something that all our current robots, Cybertronians, and other outright futuristic characters had to contend with and it would be a bit unfair to make an exception. However, pretty much everyone who has had such appearance modifications still uses the regular icons. Most don't make special ones just for this. The changes can also be minimal, and you could lean into more of an "arcane construct" angle than steampunk.