Hey man, I know it's been a long time since you posted in your Phantasy Star Zero undub project, but I was wondering if it was possible for you to make a patch that only adds the JP items into the US version, without changing anything else?
I may try the new ram site, and download more RAM to my Switch. Not sure if ddr3 is the right ram
for it tho. Edit- no it uses floppy Ram, just like @AncientBoi