Same. I considered switching iCloud accounts when I switch between work/personal modes but decided that the risk of accidentally leak information between account or losing data was too great.

At least with the Macs I can create a separate OS user account and have that account signed into the other iCloud account. Think iPad OS will support multiple users some day?

Then you may be able to use Airplay to project your display onto that managed Mac.

Is there a reason that you don’t login to iCloud when you are logged into your work iMac? You can control which data is shared between them if you want to keep personal stuff out of the work computer.