This might seem like an odd question from an experienced solver but here goes anyway.

Can a puzzle with a uniqueness pattern actually have more than one solution that fits the clues ?

Just to make the question more concrete consider a puzzle with a 4 cell UR plus one guard digit (that prevents the UR from being exposed).

Is it possible, that if the guard digit is eliminated, the UR pattern would fit the clues (so that the puzzle would in fact have 3 solutions that fit the clues), or is that regarded as cheating by the puzzle creator ?

As a solver, whether this is true or not makes no difference to me. If the puzzle did have 3 solutions I know that the solution that is being looked for is the one where the guard digit is true, so I ignore the 2 other possible solutions and place the guard digit.

It doesn't bother me what the answer is, but the question came up in another forum where a contributor commented that a puzzle with 3 solutions (2 UR solutions plus one with the guard digit True) was a badly constructed puzzle, and I'd like to be able to reply to their comment.