I must admit, I only SKIMMED through your entire message, because I know EXACTLY what you are asking. My question to you though, did you try this slideshow on mobile BEFORE the last update?
If you did, you would have noticed the following (on mobile devices):
- On page load, the slideshow would correctly take 100% available height.
- When scrolling down, the browser URL bar would automatically disappear, technically resizing the browser area, and causing TWO major flaws with the slideshow: A) Since the slideshow height increases, and you have set to COVER mode, this means the image inside will suddenly increase in size on scroll, to match the new height. B) If you are scrolled to bottom of page, start scrolling upwards, the browser URL bar will re-appear, effectively changing the height of your slideshow at the top ... This of course makes all content below the slideshow JUMP.
- Repeat this issue every time the scroll is toggled up/down when the browser URL field displays and hides.
BOTH the A/B effects noted above create awful glitches to a page with slideshow set to 100% height.
THEREFORE, we chose to LOCK the slideshow height on load. The height the slideshow displays at will depend on a few factors: If the browser URL field is displaying on page load, and if the browser url field is displaying on device-rotation. But YES, when scrolling around and/or rotating the device, you may end up with a slideshow that may cover slightly more or slightly less than the visible area ... This is because we need to set a fixed height to prevent the height of slideshow from scaling up/down WHILE scrolling ... Thus, to prevent some awful UI and layout-thrashing, the height of slideshow is locked on load, and will not always be identical to height of browser visible area.
Hope that was understood without me having to create a video.
If you have any examples of other non-X3 websites with 100% slideshow/intro image, I can show you that they either have this bug where slideshow resizes on scroll, or they have implemented a similar fix.