-The number one problem is still missing the "quicksave" promt. For new players who have nor parsed the UI yet the promt is just not visible enough. I'd say go ugly big on this one. Maybe progressively growing font?
We can take a page from Ludeon and Rimworld on this one, since in spite of a few minor hangups here or there, RimWorld's UI is almost always top notch:
1) "Marquee entry"; along with an audio cue, any new alert will actually appear a few pixels away from its original location and then drop into position. This movement exploits the eye's natural tendency to track moving objects and is an excellent attention getter.
2) "Bouncing"; every so often, an important alert will "bounce" on the screen; it will travel in one direction a few dozen pixels to the same distance it would have when it appeared, all the while decelerating as if affected by gravity, until it accelerates into the opposite direction and falls back into its original position. (In RimWorld's case, all of these alerts are aligned on the right-hand side of the screen, so they bounce to the left.)
3) "Pulsing"; if an alert letter hasn't been acknowledged for a while, it will glow with a halo according to its standard colour, enough to shade a small proportion of the peripheral vision in that colour, which then recedes back into the icon.
Any/all of those cognitive psychology tricks would work to draw attention to the prompt.
All that said, I think the best option would just be to get rid of the mandatory quicksaves and just
suggest the player do so. It's sort of silly to be forced to save the game to progress, since we've been trained over the past ten years or so to expect games to autosave on their own; especially in a single-savefile system like Starbleeper has, it's almost to the point of being contrary to our wishes to save except when we want to as well. In ironman mode it'd be fine to include a guaranteed autosave, and in non-ironman the player should have the option of saving or not saving as part of that play mode is to choose when/if one wants to lose progress deliberately by saving before a particularly risky endeavour -- not quite scumming, but close.