I put these in the task about changing 2.8 defaults but they might be more suitable here.
Some things I’ve noticed that probably fall into this category of fixups:
Render Properties -> Cycles -> Light Paths : The values filled in by default are not part of any preset. This means that if you start switching between the included presets, you won’t be able to go back to the default values unless you remember all of them. There should probably be a new preset added which corresponds to these values
Render Properties -> Cycles -> Sampling : The presets do not take into consideration the “Square samples” option. This means that you can select “Preview” or “Final” but the Squared Samples toggle remains set to whatever was there previously. This could be somewhat surprising. Additionally, I believe the presets that exist currently are only for the “Path tracing” integrator, not the Branched path tracer option; new presets are needed perhaps.
Presets in general : Would it be possible to include a “(default)” text next to any preset which is the default. For instance, the Cycles -> Dimensions defaults actually correspond to the “HDTV 1080p” preset. It would be nice if the preset was actually called “HDTV 1080p (default)”
Edit Mode -> Delete -> Edge Loops + Face Split option : Should be OFF by default. The Face split option is already OFF for Dissolve Vertices and Dissolve Edges and it produces more expected results in typical situations