Yeah, most likely not possible with that game if you've tried all that. I wouldn't buy save wizard for one save, especially not knowing if all saves can be region changed.
Most definitely not worth it only for one game.
Also, I tried another US RE2 save.
Put it in the same way that MW did in last save apollo video (PS4/SAVEDATA/0000000000000000/CUSA09193/xxxx game saves
in the root of my usb.
Opened Apollo, went to USB Saves, and downloaded each game save to my hdd.
I hit "yes" to resign to all of them.
Then I made sure to inject my org keystone so I don't get a "save corrupted message".
Game loads, and then it doesn't even read my saves. It forces me to rebuild a new sys data settings with choosing my settings, brightness, etc.
So the issue is not within the region, keystone, or param.sfo. I truly do think some game saves cannot be transferred over no matter what you do.
I wonder if someone at SW has a way to decrypt original passcode keys. I'm sure they are using something similar to sony to bypass this.
This reminds me of the days where PS3 had a similar issue with some group wanting $$$ so people could play games above 3.60 FW. That trueblue dongle crap, remember?
Anyways, i've let bucanero know about my issue on his github. I'd appreciate it if you can share my situation here with him on discord. Maybe, this issue of mine can lead to a better Save Apollo app one day!
Thanks for all the help!