Just an idea, but it would probably be nice to be able to see the battery percentage on the kindle dashboard... at which point, I thought "why not have the last update time shown as well?"
I added this to the refresh_dashboard function locally:
/usr/sbin/eips 1 39 "last update: $(date -Iminutes) battery: $(gasgauge-info -c | sed 's/%//g')"
Unfortunately, the built-in busybox date utility is extremely limited, so this is printing in UTC time (and not in a very nice format to begin with) and I also discovered that eips can't print the % symbol, apparently, so I'm using sed to strip that out.
Obviously a lot of room for improvement, which is why I didn't open a PR, but I figured I'd at least mention the idea.