I will repeat this now you all know I am not lying.
When someone gets to L-2, regardless of the game you should ask for a claim. If they are town then the claim is so that should they have a powerful role they get the opportunity to live through the night. So either you end up lynching a vanilla townie or you create a situation where mafia have to second guess whether they go after the power role or not. Either way its an improvement upon lynching blind.
If they are scum they might fakeclaim a powerrole. Nothing wrong with this, however, how long can someone keep up the pretense of a power role they dont have, and why did they not die at night? The claim still means you have legitimate evidence to catch them in a watertight error.
A townie fakeclaiming a role is one of the most dangerous plays for town there is. Why would a townie fake claim cop in a game where there is likely a doc? All it does is control the docs protection and reduce the targets for scum. Think very carefully before doing it.