Body position and bike configuration. Force RX for C4-C5 quad rider

I understand each rider has different functionality and ability, but are there some generally accepted Force RX bike configurations and body positioning for a rider who's C4/C5 with weak triceps? Should he be more upright (I hear that's the case so the rider uses more back and shoulders, taking the weak triceps out of play)? Should he be higher than normal (using extra cushions under his butt to get the shoulders above the cranks...I've already lowered the cranks as low as they can go). Should he be closer than normal to the cranks? Further away than normal? Any general advice as a starting point that's seems to hold true for most higher-level quads would be appreciated. Thank you...

Body position and bike configuration. Force RX for C4-C5 quad rider