please don't expect too much from the subject title- essentially, it is still the same old java editor with its limitations (especially elevations!! so don't use it after definition of elevations).
But- there is one new feature you might also like: "Subdivide Segment".
With this, you can split any segment (including clothoid curves) at any point, not affecting the track's alignment. So you can achieve perfect alignment of your track with the image source and align the first and last segment in the very first step- and then subsequently split it into smaller segments to incorporate changes in texture, elevation, side width, border shape, ...
short demo:
both curves were 180deg before, with radii from 30m to 200m- now the first curve has been split. Although the image might suggest it would have been split in the middle, this is not the case- it is always split on click position (bad demo).
preview2.png
Remember: this thing will still destroy heights (and more)! So you should only use it before you start editing the xml file, setting up elevations and more. If you need to split a segment later, you can still open it in track editor, split the segment, copy the values for arc and radii to your xml and close track editor without saving.
Hope you enjoy!
regards (and merry christmas, btw

Simon