8va alta can not select end note
1) Select a beginning note than add '8va alta' by use Master Palette -> Line->'8va alta' and drag to the beginning note. Then the ending note automatic select the last note of the measure that beginning note belong to. If the desired ending note is the one of the following measure the end note will automatically move to the last note of the measure of the desired ending note.
2) In edit mode the ending of the 90 degree down dash line can change to desired note but the actual ending note still not move accordingly.