The examples are hypothetical, so the primary question is how many of these translate into real-world cases. If (mostly) everyone already agrees on the same interpretation, the issue remains hypothetical.
It was not my intention to agree on using one instead of the other, but rather to highlight that if tagging everything on a single line causes issues, perhaps the solution in these situations is to not tag everything on a single line.
Using highway=* + cycleway=* to mean that there is a completely separate road meant for cycling that runs somewhat adjacent to the road represented by the line seems to be an endeavour that’s essentially dead in the water in terms of real-world practicality. You can do it, but you will face issues at some point, and when you do, the best solution is probably to draw a separate line for the cycleway. Many of the hypothetical issues raised seem to arise from this usage, but that would/will be clearer if real-world cases are presented.