I’ve done it with my laser engraver, but wouldn’t recommend using the x-carve unless maybe if you have the laser attachment and you’re experienced with it.
Got to agree with Brian. Unless you have an excellent probing/mapping setup I wouldn’t put an expensive iPad under a spindle/bit because of how this their rear skins are. Laser on an anodised surface? Perfect.
I did some engraving on my computer mouse - but that’s just a $10 risk and fortunately turned out very well:
However: I wouldn’t try this with an IPad or other expensive device - you only have one try and if anything goes wrong it will look like s**t or even be destroyed.
I’ve always been told that lasers are the way to go with case etching on phones and laptops because spinning bit engravers tend to cause a lot of vibration that can shorten the lifespan of the machine. Whether that’s still true with SSDs I’m not sure, but I also don’t think I’d bet $1K worth of electronics on it.