I agree, lines are more flexible, but they also come with downsides…
They need more user time to create them, and then what to do about display.
They should clearly show in the editor, but what about on the board ?
They are not actual thermals yet, merely suggested axes, so users probably prefer to not see them ?
Or maybe they toggle, so when thermals are visible, the suggestions vanish & vice versa ?
If you create a line, you now must support ‘any angle’ thermals.
An expectation would be Line width is going to be thermal width, but users have menu-control now, over thermal spokes. Maybe that needs another menu choice - GUI or Footprint spoke widths ?
Most users are like my example - they just want some thermals created, like other CAD pgms can do.
Anchor Pad thermals should have minimal code impact, as thermal-to-pad already works fine.
ie to me, it needs some decision cleanups, not completely new algorithms.
Anything that can avoid a database change, is easier to get done