Trivial findings:
You can order rose gold mechanisms to be made through manager at mechanics workshop.
This will cost you fuel
But you will get access to magenta and teal lever colours
Or perhaps stretch gold/platinum/aluminium into 4x as many super-valuable mechanisms. Or perhaps get more weight than normal out of gold, by making rose gold mechanisms - using 75% of gold to produce 20% of the weight per gold bar, for 6,6% improvement.
Cramming 4 kids into 1x2 minecart dodge training in 43.05 can result in 1 of them dodging once and then nothing, at least for a bit. Boring.
As I thought, it is indeed possible to exploit diagonal movement for endpoint automatic return to sender (i.e. with track stop, without danger of hitting dwarf nor requiring their labour).
Course, with the sideways velocity of just a diagonal upramp the return speed is rather small. Rather than crossing over, it couldn't muster the velocity to pass into hole
Though it would, if you used track/floor...Or alternate velocity boosting arrangement for different input/output.
(opposing NSE and NSW for boost)
'course, this used dwarven push. Different input speed, different offload point.
Watch as some dwarves fulfill their dreams of creating great works of art and mastering a skill while pretty much working as slaves. lol
After drowning in artifact furniture in a generational fortress, I've discovered YMMV on this.