An SG2100 won't work upside down even if you swapped East and west, the arc would be upside down and you'd be scanning Mars before you hit a satellite
You could cut the pole down to whatever length you'd need, my thinking is that you need as much clearance as possible to stop the LNB arm hitting the pole as well as clearance above your dish as Pete said.
You could cut the pole down to whatever length you'd need, my thinking is that you need as much clearance as possible to stop the LNB arm hitting the pole as well as clearance above your dish as Pete said.