I can add a few things, but I don't want to take up too much of your time.
The fact that the bill has been adopted at second reading sets the scope of the bill. If the bill had been sent to committee before second reading, the scope of the bill would have been enlarged, so the possibilities for amendments would have been greater.
Here, we are in a situation where the bill has been voted on at second reading by the whole House. In a sense, the whole House agreed to what can be amended. Therefore, there are ways here and there, but they're very narrow in terms of the parent acts.
In terms of bringing in witnesses, I can't really comment on who you should bring in, but you should keep that in mind. Once the scope of the bill is set, it's difficult to go beyond the scope, because that's one of the rules. You can't go beyond the scope of the bill, unless, of course, it's sent before second reading, whereby it opens up a bit the possibility of amendments.