Restrict the upload of document types without the compliance kit?

There's no built-in configuration option for this, so you need to either use one of the add-on modules (recommended) or develop an event handler for this yourself.

Hi Jonas, Which would be the best add-on to do this? I have been looking through the compliance kit options, but I'm struggling to find what I need.

Hi Jonas, Which would be the best add-on to do this? I have been looking through the compliance kit options, but I'm struggling to find what I need.

I would have a look at Property Calculator like suggested above.