[Question] Downgrade sysNAND with agb firm patched?

Hi, I can't seem to find any information on this.

1) e.g. I have a 9.2 sysNAND with agb and twl firm patched. I update it to 10.7, will the patch still be there? Same question for emuNAND too.

2) If it is still there, when I downgrade sysNAND will there be any issue? Lets say I accidently update sysNAND to 10.7 and I need to downgrade it back to 9.2.

Thanks in advance for any replies!