If fdic insured only at 250k and if you go over that threshold, it should be ok too. I probably wasn't even alive when fdic was involved in paying out so lets say that we go back into a depression and fdic only pays you 250k but you are a little bit over it. I say to that they can have the chump change.
I mean seeing your account at 251K is better than having to micro manage like you have to buy something to drop it lower than 250k.
Peace of mind brother. Live in fear not.