There are a few things.
First of all, it does not remove the MP from the seat. It prevents an MP from sitting or voting. They'll still carry out all the functions of an elected representative.
On the matter of whether there could be more clarity in the legislation, maybe. One thing I would point out is that, first of all, these letters are rare. It points to the effectiveness of the mechanism. Again, these don't come as a surprise to the agent or the MP. There's been extensive discussion, several correspondences exchanged with regard to the issue at hand. There's advance notice that if we can't resolve this matter, then that letter to the Speaker would come out.
Again, it's been very effective in ensuring timely and accurate filing of returns.