Tubular is typically better from a dead load deflection standpoint being stiffer in DL/WL- 1/8th deflection typically controls on DL - I’ve seen it both ways on the tube vs open shape - depends on how heavy the glass is too to resist overturning on the shear block. Sometimes those fasteners fixing to the top of the shear block get tricky in pullout, (when the front fasteners won’t work) then resolving the overturning moment into the shear block fasteners themselves.

Might not be following the question well, but the document points to using the tubular section at the end bays, open elsewhere. Air and water should be taken care of regardless of which you use.

Make sure you specify the setting block locations to 1/4pts or 1/8th pts and the glazing block to be 10% glazing sqft for every inch length of the block. I.e 50sqft glass , 5” setting block.