The background companies we go through here in the US aren’t “random people” and you sign a release of that information for them when they start that background check. So you’ve given them permission to access that info on you. I don’t know what HRs your dealing with but if it’s random hiring managers asking you then they have no idea what’s in a typical background check anyway.
California is actually one of the states that require pay out of unused PTO. I believe MA, CO, and LA do as well, Im not sure of all of them. More than half don’t require it, in those states it’s company dependant.