Keeper.sh now publishes one iCal link that combines every calendar you have connected. Copy it from the integrations page and subscribe to it in any app that accepts a calendar URL: another calendar app, a scheduling tool, or a colleague's calendar.
The subscriber gets your busy time from every source in one subscription, instead of one subscription per calendar and the job of keeping that list current.
The link carries availability, not detail. Someone reading it sees the hours you are unavailable without seeing what you are doing in them, so you can share it with people who have no access to your calendars.
Shareable calendar links covers what a link carries and who can read it.