I honestly don&#x27;t know what you mean by saying mobile phones are abysmal at multitasking (multi threading? Multiple processes? Drawing Multiple UIs?). Mine doesn&#x27;t seem to have a problem with multi threading or multiple processes and the only reason I don&#x27;t use it more is because the UI is horrible and I can&#x27;t replace it.  
Also if your source files are long enough to slow your editor down you should probably start factoring stuff out (long files are hard to read), but I&#x27;ve never heard of or seen that actually happening IRL.