[mlyle]

What I'm saying is that the first variable layer is of relatively constant thickness, compared to previous approaches which attempt to taper layer thickness to slowly introduce curvature.

The problem that results is the actual dynamics of the extrudate varies a lot, going through a fixed size nozzle: there's a relatively limited range of shapes that do not excessively impede flow (and risk jamming/clinging to nozzle/dragging) and are sufficiently smashed into the previous layer. So if you have layer thickness varying a bunch over an otherwise continuous layer, pretty easy to have poor adhesion in many places or pressure building and later overextrusion.

Also there's a fair bit of lag-- often hundreds of milliseconds- between extruder movement, pressure change, and extrudate geometry changes. When you're moving the nozzle at, say, 100mm/s over the surface, the uncertainty of this lag translates to a big uncertainty of where on the part extrusion thickness changes.