Ann: Change in substantial holding from OZL, page-23

My reading seems pretty clear. Prior to 15 days after the bid commencing (which may be next week?) if a superior TO offer comes in Appian can accept and the new bidder gets their shares. After 15 days then in the event of a superior TO OZL keep the Appian shares but are required to make a cash payment to Appian for the difference.
Any superior TO offer will have the BR shares and OZL will be on the register with a big chunk of shares unless they decide to accept the offer also for the Appian shares.
A TO offer prior to the end of the 15 day period would make things 'cleaner' for the new bidder.