It turns out that for “Asio in” the all the channels don’t show up until the project is reloaded. For “Asio out” there is no way to select more than two channels.
Also now found another bug with asio input. The inputs are not showing up on the correct channels and are inconsistently changing. For example (on a 20 input interface) if I have audio coming in channels 1&2 (hardware) sometimes they show up on channels 15&16 sometimes 19&20 etc.
BTW this is all on a Focusrite Sapphire Pro40
thanks
Keith