There is no Tax Information available for HANA Optimized Business Content ADSO for Billing /IMO/D_SD31. In Old Standard Infocube 0RT_C01 there was seperate Keyfigure for Sales with tax and without tax. But in the transformation for new ADSO
TRCS /IMO/SD_IS31 -> ADSO /IMO/D_SD31, the TAX field is not mapped.