Two Dads actually told me that CASA is producing a CAAP on the topic. For PVT and AWK, the choice is yours, however the documents (ie maps) cannot be amended in their electronic form. Once they actually amend the charts in line with the AIP SUPs, this could actually alleviate the problem of so many people not being aware of WAC amendments.
SUP H94/10 for those of you who haven't been told about them. Have a read.
You cannot mark a track or record position fixes on an electronic document and the GPS function on an IPad is DEFINITELY NOT to be used as primary navigation.
Be warned: If an ops manual states you must carry charts and maps, electronic form may not satisfy this requirement. You are bound by the ops manual requirement REGARDLESS of any CASA regs.