I made a 2 minute video to show what I mean: https://vid.me/Do3f
Before iFly version 9.6, certain Instruments would disappear on their own (uncommanded), depending on whether iFly thought they were redundant. For example, if you have the FINAL Name Instrument and the Waypoint Name Instrument in your Layout, then whenever you're on the last leg of your trip (where the Waypoint name is the same as the Final name), the Waypoint name Instrument would disappear. Similarly, if you had Distance to FINAL and Distance to Waypoint, the Distance to Waypoint Instrument would disappear on your last leg. (Because they would show the same.)
That bothered me for two reasons: First, my eyes are used to looking at certain locations for information. (It's the same uncomfortable feeling you get (especially at night) when flying a new airplane and your eyes don't know where to look to get MP or RPM info. (E.g. going from a C-152 to a -172.) Second, I don't like Instruments disappearing. To me it's like saying someone taking the VSI out of your panel after you're reached altitude saying "You don't need that anymore. You're flying straight and level."
Okay, yeah, I hardly look at the VSI in level flight and don't need it. But it bugs me when things are missing from my scan. (I'm probably Obsessive Compulsive.) Gives a "something's wrong," "missing teeth" sort of feeling. I find it distracting.
So, prior to v9.6, I used to "double enter" my Destination as a work around, to fake out iFly. (So that the last waypoint was always the destination and all the Waypoint Instruments persisted.) That faked out iFly. But it screwed up Flight Plan filing.
Then I noticed in v9.6 up until v9.714b, that the Instruments persisted. So I took out my double entries.
If anyone noticed and/or was bothered by the Instruments persisting, I didn't see anyone squawking about it in the forums.
Now, with v9.7.19 and on, the disappearing Instruments are back.
I suppose the first question should be: Should they disappear or should they persist? (There's probably a fair amount of logic in the code to do this, and simpler is usually better. And too, there's no indication as to what Instruments will disappear when other Instruments are present. So users can't tell in advance what's going to disappear.)
If some users want them to disappear, then can iFly make a check box in the Layout box to Allow Instruments to Persist?
Hopefully the video will help explain better.