A question about Fs and Main compatibility

Sorry for my bad english.
I read the pinned tutorial related to flashing SE phones. It says that main and FS need to be the same version, but I have seen that many times it's possible to flash a FS version higher than main.
Do you have confirm of that?
By example I take a look on download section and under W810/firmwares/R4EA031_RED50 I've found a GENERIC MAIN R4EA031 and a FS R4ED001 EUROPE_5.
Someone could give me a confirm?
Many thanks in advance.

P.S.: last week I made a test doing the opposite thing; the flash process were terminated successfully and my phone works fine but without the correct language pack :D

I think you don't have to be worried.
you will get a higher stability when the MAIN version and FS version are the same.
but it still can work with different versions. i've tried many different situation,they still work very well. but, maybe you will get problems some certain conditions.
sorry for my bad english.

It is best that you use the same version of FS and Main. Sometimes if a different one is used you could run into problems. I would recommend you use the same version.

I fully agree with dyker837. You should use the same version of main and fs.

Nice day

I actually am using a w810i and i can tell you for a fact that the R4ED001 FS works completely fine with the R4EA031 Main. I don't know why but they only had a few FS for R4EA031 and I have yet to find a MAIN for R4ED001. So I can only assume that R4ED001 is actually ment to be used with the R4EA031 MAIN. But like I said, you can be 100% positive that the R4ED001 FS will work with the R4EA031 MAIN