How do I trigger an autocommand action after the cursor has been idle for a set period?
CursorHold
The CursorHold autocommand event fires once whenever the cursor has been motionless in normal mode for updatetime milliseconds.
Tag: events
How do I register an autocommand that automatically removes itself after firing once?
autocmd ++once
The ++once flag, added in Vim 8.
How do I create and trigger custom autocommand events in Vim?
:doautocmd User MyEvent
Vim's User event type lets you define custom events that fire on demand.