Just found this Q&A which seems to confirm as well.
A24.2 & D2.3 Hex B1 has a Building. Hex B2 is Open Ground. Hex C2 is Open Ground. Hex D2 is Open Ground. Vehicle in Bypass of B1 on B1/B2 hex side CAFP B1/B2/C2. Smoke in hex B2. LOS comes through D2 then C2 to CAFP.
Does the Smoke hinder shots to/from the CAFP along that LOS?
And in agreement with all... LOS is traced from the w34/w35/x34 CAFP (not along the bypass hexside)... if the vehicle fired at X35 the smoke hexside would affect the shot.
The one exception I know of for the smoke adjacent bypass is when your afv (or infantry in this case) is not in normal bypass but instead on a narrow road (village terrain) it would be IN smoke for all shots.
Its because your visualising that the StuG is straddling the HEXSIDE (my emphasis) cause thats what we do with the cardboard counter thingys that we are moving around (or their VASL pixulated equvalent)
the important bit to remember is that the StuG is ACTUALLY in the few meters of space between the hypothetical invisible but important hexline that is visible only to the God-like being that is Jim White (or me or anyone else who plays this game and therefore deserves to be treated as god like !! lol (apologies to any real Gods out there obvously)) and the dirty great big building in W34 (which is where the StuG is actually parked)
And the smoke isn't there - It ends at that previously mentioned hypothetical invisible but important hexline