Can we use -OpenDocumentsMode as parameter name ? Maybe also add an additional check to determine if the list is actually document library , I think the template enum was 101, if not add warning this wont work ?

Changed the parameter name as suggested. Just tested doing this for a normal list and it doesn't return any errors. I personally think we might be introducing more problems than we're solving things by trying to add a check for the type of list. It probably works on other types as well, what if content type inherited from, etc. I'm tempted to leave the check out. What do you think?

I now see we're actually using the doclib check already, so I guess it does work well:

Let me add it for this PR too then.