Hello so the good news. I found a fix-(ish) that the only possible way is to reinstall an original Apple SSD (which thankfully I still have) in order for the firmware to update by reinstalling the latest OS, and then reinstall back the OWC drive. So far I checked online and it seems like the firmware is the correct version now, and so far no more crashes phew.
Now the bad news. As I proceeded to DIY I believe the battery definitely needs replacement now even if my system report claims the battery is still normal. It seems like the battery has expanded and there is no way I can close back the back cover (as a result I've lost a few screws so it's not properly sealed. So I guess at this point I need to bring it to a proper technician to replace the battery as I found it is not an easy task and not recommended to DIY.
Edit: Before I forget, here's the latest etrecheck report -