I do have some of my milsurps stored with bayonet fixed (and sheathed). Its a good way to ensure the bayonet stays with the rifle its intended for.
There's an old saying that in a knife fight, the
winner goes to the hospital. Loser goes to the morgue.
If the bayonet is off the rifle, its a knife. If its on the rifle, just why would you be using it? (see my previous post).