Samsung rom downgrade
I currently have a Samsung exynos j400m that have rom updated to spl after mar/22 (so, no working bootloader extraction) . The current rom is bit E and I wasn't able to downgrade since there's no bit E with older spl in roms for my country.
So, wen I looked at samfw I was able to find some rom with bit E and spl dec/21, but from a different country. Then my question is, could I downgrade temporarily using this rom from a different country since I will use home_csc to not wipe the data? Sorry asking this this I currently don't have the same device as test phone to check it.
In general yes, that's possible. CSC doesn't have to match and as long as you use HOME_CSC file, you should be ok and data will not get affected.