Congratulations! You are the FIRST to locate the serial port on an Oasis model!
I would suggest you start looking at this thread for some guidance:
https://www.mobileread.com/forums/sh...d.php?t=267541
Hopefully it is applicable to your model as well. I have not had to do a serial jailbreak myself, so I have no personal experience to fall back on.
Hopefully you will gain the attention with this thread of those who had hoped to jailbreak their KOA for a long time and those who have serial experience to offer guidance. If it is not quick in coming a PM to some of those who have done so might help.
Dave