We've moved away from Link because there are too many constraints for an already basic portal.

As Jeff says, you'd need a lot of luck for this suggestion to go through but I've upvoted this regardless (getting rid of the downvote was probably the only suggestion Intuit accepted from us, thank goodness).

You may like to take a look at Verifyle as an alternative.  A number of CPA's and tax pro associations have deals with Verifyle.  It's worth checking out.

You'll get much better control with Verify and you do get notified when your client view or download a document.

You and your client can also e-sign documents, including the likes of F.8879, without charge.  On their website, they have a document that lays out how KBA will work based on legal advice they received.