Best I can tell, all of the Honda engines I've worked on use ignition to fine-control idle. The pre-drive-by-wire vehicles had an idle valve that let in more air when cold, whereas the post-DBW vehicles would simply crack the throttle plate, but both retard ignition significantly at idle.
Take the K24 I'm using from an Acura TSX - it's ~8 years newer but functions the same way as the Insight stock engine in this regard, or our Fit. At idle I'm generally seeing ~5-7° ignition advance. When I flip the headlights on or toggle the A/C it jumps maybe as much as 6-8 additional degrees momentarily to hold the idle perfectly steady, and then levels out at 1-2° more advance to hold the same idle speed. Touch the throttle lightly and it's instantly at ~24° advance, which is ballpark for MBT at that load and RPM.
Here's one of the timing tables my car uses, for example:
Idle timing uses separate logic, and there are different tables for every 10 degrees of intake cam advance, and separate tables for all of these in and out of VTEC.