I got some weird results slicing engraved lettering, and the more I fiddle with it, the weirder it gets.
To test the issue, I made a plank with lettering engraved at heights (up from the baseplate) from 0.1 to 1.0mm:
Cura brings in the STL fine (the 0.1 is hard to see but present, the 0.2 and deeper are clearly present.)
If I slice at 0.25 layer height and inspect layer 1, it does no path at all for 0.1 and 0.2, and layer 1 gets 0.3 and deeper. This makes reasonable sense.
What makes no sense at all to me is that if I reduce the layer height at all, I actually lose detail. Here, I reduce the layer height to 0.06 and view layer 1. What I would expect was to get at least the 0.2 lettering, and maybe the 0.1. Instead, the 0.3 also disappears!
WTF?
(I've posted the STL here, if anybody wants to duplicate; I've duplicated on two different PCs, and I've tried varying bottom thickness, fill, and nozzle without making any difference.)