Mechanically my main issue with range restrictions on admiral's is that it really hurts high mobility fleets which I think is a bad thing.
This is my main beef with the idea. It actually limits fleets well beyond just flotilla camping.
Imagine a mission like Station Assault where your opponent puts the stations literally on opposite sides of the board (Which Caldias likes to do). You HAVE to split your fleet to go for them both.
Limiting admiral ranges would just lead to the best tactic always being formation flying. It locks down commanders who may gain benefit from ships being more spread out, like Mothma corvettes, or Sato.