automatic hyperlink transitions

Many times in this Forum I have suggested creating "sub-sets" of presentations and linking them together via Hyperlinks into a complete presentation as a means for playing audio over a series of more than one slide in a slideshow. (This is in the absence of the ability of Keynote to play an audio track over a group of slides - a feature that we all hope will soon appear in a upgrade to the application.)

Yes, this is cumbersome but it does do the job ... somewhat ...

The problem I have (which others have also noted) is that Hyperlinks do not produce a smooth transition from one presentation to the next, and that they must be triggered manually (by a Click on a dedicated "icon") at the end of one presentation to initiate the next.

So, the following questions:

1) Is there a way for a Hyperlink to be triggered automatically at the end of the last slide of one presentation to begin the transition to another presentation?

2) I know that, at present, Hyperlinks go "black" between slideshows, so that if the last slide of one and the first slide of the next also are full black, it will be less obvious during the transition. However, there is still a certain "jerkiness" to the transition - especially when the Hyperlink "icon" suddenly disappears from the exiting slide. So, Following on the previous question: Is there a way to make this whole process more streamlined?

Thanks to all who read and respond to the questions in this Forum