I tested this manually myself last Thursday, June 18, 2020:
Bulk ticket transfer
enabled means that Agents are prompted to transfer their active and idle tickets when they manually change their status to Away or Offline. They can pick which team receives their tickets. If they sign out of their account or X out of the browser, tickets are not transferred.
Bulk ticket transfer
disabled means their tickets are transferred automatically when they manually change their status to Offline, but not Away. Tickets are also transferred if they sign out of their account, but not if they X out of the browser.
There is no workaround because Agents will forget to manually sign out.