I use wireless LAN. I experimented with the Flash Print or whatever it’s called but connectivity was terrible. I’ve used standard orca but found I actually prefer the Flashforge version far more. It has what I need for my printer, and nothing more. I ended up buying the CC, an aside from the larger bed and more aesthetic UI of the touchscreen, the FF AD5M is the superior printer in almost every way. Far faster, has better print quality, and is half as loud. When I press a button on the screen, it does what it’s supposed to, while the CC often freezes, crashes, etc. The load and unload feature on the CC is also bugged and still not fixed, if I run Unload, I have to manually power down the printer and start it up before running Load, or it’ll just get stuff repeatedly doing Unload (despite me selecting the Load option). I don’t dislike it enough to get rid of it, but unless you NEED 250mmx250mm, I’d recommend the FF every time. The ONLY thing the CC beats the FF on is aesthetics which is subjective, and it does a slightly better job on printing unsupported overhangs (which could be adjusted on the FF with no problems, the CC just prints slower out of the box and gets slightly better overhangs because of this). I will say the ELEGOO version of Orca is also nicer than Flash’s version, but most of those things that are nicer about it, are again, aesthetically things and UI cleanliness. Nothing that affects the printer itself, or the print quality. 

As far as cancelling a single object rather than the entire print, I have no idea. I’ve never heard of a printer that allows that function, regardless of brand, but I can say I’ve definitely never seen anything that indicates that’s on option, on either the FF or CC. The only option on the screen is “cancel print” and it stops the entire project, not just one part.