Adding MULTIPLE "stops" for Visibility and/or Animation

I’m working on a new slideshow and trying to create the appearance of a particular layer on a slide to have it appear, then disappear, then reappear again. With a bit of work, and using a number of slides in succession, it can be kludged together, but it’s messy and time consuming, and it means the timing from slide to slide, even at short intervals, still seem to take longer than wanted.

I would like to see the ability to have multiple START and STOP points for any layer on a single slide in the Visibility slider, instead of just the two currently allowed. Start with a layer visible (or not), then bring it to zero (either abruptly or with a fade out), then bring it back up (abruptly or with a fade in), as many times as the user wants (within reason, of course!)

It would be nice to see the same ability on the Animation slider adjustments as well – a layer could animate, then stop, then start up again from where it left off, then slow down or stop again, etc.

I’ve also suggested before about putting actual CLICK stops along the Visibility and Animate adjustment sliders to allow for consistency of those aspects between slides (yes, I know copy/paste geometry works), but sometimes it would be nice to move the slider adjustment knobs and have them “click” on one of the timing lines within the slider.