As Lexel write there are another limiting current resistances, like PCB copper thickness, pcb width traces must be huge for lower resistance and so on. It will be interesting to view how much power PCB board can dissipate from MOSFET to host which is main limiting factor for that driver. For best results the board must be 4 layer design and small thickness. So that driver is very similar as Texas Commander approach from 2 years ago Texas Commander "TC" Constant current Opamp driver without PWM . Aslo very interesting project which has been abandoned for thermal issues with heat dissipation.