Why is this not implemented?

The other point that I think Vio makes is that on the 1 piece curved slope rail the slope actually tapers off at the top and the bottom and goes flat - just for a very small section.

When you build your own ramps using a normal curve (R-03) and a small riser the incline continues through the track join and hence doesn't really connect to the riser (which has a flat top) properly, causing instability.

I have a lot of the dark blue and light blue (hard) versions of these parts but I have not seen the 2019 (soft) version. I also wonder why they did not make a double track version or a version for R-09 (outer curve).