It is possible to tag the elevation of the high end and the elevation of the low end but autocad architecture cannot make the distinction of which end is which. The same situation applies for tagging the elevation of sloped pipe.
You can create two tags called startend and lowend. The start end would compare the elevation of the start end with the elevation of the end and it is is higher then it can say higher or if it is lower then it would say lower. The same goes true for the other side. You would just need to always tag the startend tag at the begining of the structural member. This is made easier by the block that you have added to the member symolizing direction.
