I really don’t see the issue. If the work account uses Google or Microsoft I use their respective web apps and export an ICS link to see the blocked slots in my own personal calendar.
For my own personal calendar I use CalDAV, which is widely supported, and an app that can import ICS links. (Self-hosted Radicale server and the Calengoo app for mobile and desktop, for the curious.)
I really don’t see the issue. If the work account uses Google or Microsoft I use their respective web apps and export an ICS link to see the blocked slots in my own personal calendar.
For my own personal calendar I use CalDAV, which is widely supported, and an app that can import ICS links. (Self-hosted Radicale server and the Calengoo app for mobile and desktop, for the curious.)