Stock FJ09 R/R is MOSFET shunt style, Shindengen FH020AA which is also used in FJR1300, Super Tenere and many other bikes.
Shindengen SH775 is a SCR series style and a drop-in replacement of FH020AA. However FH020AA is rated for 50A while SH775 is at 35A. In addition, FJ09 puts R/R in an undesirable location where there is very little air flow.
I retrofit a Shindengen SH847 (SCR series 50A) into my FJ09 with some mechanical efforts. Electrically it's straightforward since SH847 has identical connector pinout as FH020/SH775.