CQC wouldn't know or care if there were was more than one. You just load two instances of the driver and point each one at a different bridge. You'd have to configure each driver separately for the modules that are attached to their respective bridges.
Now, whether this works without issues and will continue to, none of us can say. Lutron might not like that and might do something to prevent it. Seems unlikely, due to technical issues (two people in adjacent apartments for instance.) But, we obviously can't guarantee you it will work now and or in the future. It would have to be tried.
Other folks have reported doing it, at least that I've read. No CQC customers have done it. But there's nothing in CQC that would prevent it, so if it works in terms of Caseta itself, then CQC wouldn't have an issue with it.