I finally solved the savedata dumping compatibility by changing cart flasher to GBxCartRW 1.4a Pro and removing the RTC battery.Not 100% sure as i just use regular diodes when i do this mod, but It looks like a dual schottky diode so should be fine. Middle pins might be no connects. See if you can see a code on that chip and look for a data sheet but it should be some form of smd diode array.
It seems that the circuit doesn’t block the RTC-battery to FRAM’s power supply:
Could you help me point out what should I do for blocking battery-FRAM powering with this mod?
BTW, I also tried modding Pokémon Crystal Japanese (1Mbit save).
But it’s working on 4.32V which is over the nvSRAM IC STK14CA8’s 4.1V max.
I asked BennVenn and he said there are no solution except transplant the mask ROM to a new designed PCB for 1Mbit FRAM/nvSRAM with level shifter that workable on 3.3V.