I'm careful when I have to work on a sloped area, but maybe overly so.
I'm assuming that the advantage of a tilt meter would be to provide an objective appraisal of the tractor angle?
Is there a rule-of-thumb that can be used to determine what is actually unsafe vs. just uncomfortable?

I don't want to operate anywhere near an unsafe tilt area, but I suspect that I'm being too careful, in some instances. The tilt-meter likely won't change my attitude toward working on a slope, but it would be nice to have an indicator other than an accelerated heart-rate when you feel your center of gravity shift!