Why does fx-9750GIII contain "Imp Multi" option

[stanchcorder6 Profile]

fx-9750GIII contains an "Imp Multi" option. If this option is on, the priority of implied multiplication is the same as TL/W series, MS series, ES PLUS series and Classwiz series. If this option is off, the priority of implied multiplication is the same as ES series, fx-71F, fx-50FH and fx-5800P. Why does only fx-9750GIII contains this option but fx-9860GIII and fx-CG50 don't?

Example:
Imp Multi On: 30÷2(2+3)÷5=0.6 (same as fx-82MS, fx-991CW, fx-72F and fx-4850P)
Imp Multi Off: 30÷2(2+3)÷5=15 (same as fx-991ES, fx-71F and fx-5800P)