Thank you @lsaa. Firstly the lower back corner choice was for getting the pipes out the way, secondly to try and get the airflow downwards as the printer is quite open at the top. It is an attempt to get the bad smells/smoke to not leak out the contained area.
Also getting smoke out the way for Laser to see what is happening. When cutting I want to add Air Assist to the Laser, that means the smoke will exit below the item being cut. For multiple pass cuts, the smoke is generated on topside, but still low on the bed. I want to keep soot and deposits from the sliding mechanisms and worms as much as possible.
Only the side panel where the fan is was sealed, not the opposite side, it remains unsealed. The slot on top between the covers was also taped over, glued on one side, but that is not working well atm. Wiil have to find better way as the filament for printing pass between the covers. My filament is in dry boxes above the printer.