hi, Len. my MB is vertically mounted in the case. I cable-tied the delta
card and adaptor together, and as you guessed, the case more-or-less
supports the outer edge of the card. The adaptor came with a support
bracket which I also used, though on its own it would be a little droopy
for the width.
I used the lowest available slot, but in any case there would be no
obstruction to general airflow.
~G.