How do the other user know the mapping even if you implemented 5.1 ?
I don't know (?)
https://rog.asus.com/forum/showthread.php?54685-Asus-G751JT-supports-5-1-ana...
Is the support of 5.1 done by realtek hda manager or asus audio wizard ?
I have only used Realtek HDA Manager. There's no "wizard", you just have to select 5.1 Speaker in Speaker Configuration drop down menu.
Do your 2.1 work as expected after enable pulseaudio 2.1 lfe filter ?
Do your dual headphone jacks work as expected after you add back the missing pin?
Do your dual headphone jack coexist with 2.1 speakers since you only have three volume controls ?
After you change to 5.1 by realtek hda manger , do you need a reboot ? If yes, Do this mean that you also need another reboot to use back 2.1 intenal speakers ?
Do HDA realtek manager allow you to
a) change mic jack as Line in jack ? b) disable the subwoofer ? c) change any jack to line in, line out, headphone or mic ?
Since bios did not setup pin default for some jacks,
Do users expect the jacks are initialised by the driver
1) as the icon near the jack 2) as specified in user manual 3) as notebook specifcation
You need a simplified verion of hdajackretask which allow you to change from 2.1 to 5.1