"and where might you think the company would obtain this data from to have up to date registers"
The only place where ISX can obtain a 100% accurate list of company members (shareholders) is from Computershare. This is due to ISX having a commercial arrangement with Computershare to maintain the company register - ie, they pay Computershare to maintain the company register on behalf of ISX.
An accurate ISX company register cannot be provided via CHESS, however CHESS update Computershare of the latest details that are held inside CHESS.
I would suspect that ASX was seeking a 100% accurate list of the members if ISX. This can only be provided for ISX by Computershare (on behalf of ISX).
