I have a similar problem to the one described in https://discuss.atom.io/t/lag-crash/22854/5, but Atom doesn't crash, so I thought I better make a new message... (That's why I chose the Features category, not the Support one.)
At home, I have a rather old computer (with Windows 10 now) often nearing filling its 4 GB of memory.
When I start Atom, or when I activate it while its memory was swapped out after a while of inactivity, I get the above described message:
Editor is not responding
The editor is not responding. Would you like to force close it or just keep waiting?
Keep Waiting / Close
The message itself is rather OK. If I click Keep Waiting, the editor often resumes. It is nice that Atom is aware of wait time and responsiveness.
The main issue is that this dialog is modal and blocking.
I saw a similar dialog in Chrome, for example. But at least, when the browser resumes (swapping ends, for example), it is able to auto-close the dialog, as it is no longer relevant.
Here, I can wait a long time, I haven't seen any auto-close, and the editor is indeed reactive when I click Keep Waiting.
That's all: a suggestion to keep checking if the editor becomes reactive while displaying the dialog.
And perhaps a way to adjust the time before displaying the dialog, for old computers...