If you are an EA or a FC, look at it this way: How are the S&C positioned on most rings/pins/caps/stickers/etc.? Both legs of the compasses are on top. Is that the position in which they are placed to open an EA or FC lodge?
I think of it as if when I was in the Navy and a Petty Officer 3rd Class ... let's say one day I decided to wear the insignia of a Petty Officer 1st Class; that would be OK, we're all in the Navy, right?
*(that's not an illustration to suggest a MM "outranks" others in the lodge, rather to show there are differences in insignias)
If your jurisdiction allows it, that's fine and your right. My jurisdiction does not. EAs and FCs are considered Masons, but they aren't really considered lodge members. They don't pay dues, don't vote, don't attended stated meetings, aren't listed on the lodge rolls, and don't have anything identifying them as Masons (i.e. dues cards). EAs and FCs can only go to degree work equal to that of which they have received. If traveling to a lodge other than their own, they must be accompanied by a MM.