After reading this post (credit @centaur)
https://forum.openwrt.org/t/support-for-gpon-sfp-fgs202/42641/53
I decided to stop the clutter of cables and constructed a simple cable that takes up little space while allowing me access to the MA5671A
I didn't have to use an external power supply because the USB TTL adapter provides 3.3V DC
Connection diagram
USB TTL(UART) Adapter ---------- SFP 20pins Molex connector
3.3V -------red ----------------------------pin #15 and #16
TX --------orange ------------------------pin #2
RX ---------yellow ------------------------pin #7
GND ------green ------------------------ pin #10
IMPORTANT! Use GND wire as ON/OFF switch, otherwise there will be a slight delay before data is displayed on the console (putty/TeraTerm)
