I'm having the same issue myself.
Had a bottom pull low band Nexave mech, needed a top pull.
Have an STX top pull high band, wrong band size.
Bought a Nexave top pull low band.
The cable enters at the wrong angle, the stops on the frame want the cable to the drive side.
Mine works but runs over the lever and snags my mudguard.
So I'm looking for a Nexave top pull high band 28mm mech. Or some DIY bodging swapping levers/bands if possible.
Bottom mech: Nexave low band top pull, cable enters wrong side.
Top mech: STX high band top pull, cable would enter correctly.
Left mech: STX low band top pull, cable would enter wrong.
Right mech: Nexave low band bottom pull, cable on right side pull wrong direction.
A low band top pull = cable non drive side.
A high band top pull = cable drive side.
A low band bottom pull = cable non drive side.
A high band bottom pull = cable drive side????