TEACHERLIDOO TIME
ouran wanted help with making this with the new system.

The most important thing to note is that, again, the midpoint passes through the middle of the slider. Exactly through the middle.

A good approach for aligning arcs across an axis would be as follows:
Draw two points, so that the slider begins to draw.

Move the second point up until the slider extends onto the axis. This will be roughly where the middle tick will sit.

Then, place the third point symmetrically.

In this screenshot, the end hasn't aligned properly. Fear not! Move the midpoint down by either one grid4 or one osupixel at a time until the end snaps.

SHAZAM! It's now aligned perfectly. I mean perfectly. I'll also say this again: The slider will also align perfectly if the midpoint is moved asymmetrically:

For those who like to stick to the grid--even when using grid3--this will be more ideal, although it takes a bit more work. It's much more straightforward to take the midpoint out of grid snap and move it down until the end's aligned. This is exactly what had to be done with beziers, so
it's not harder to do.Also, note that the end might still be a few pixels out, but the new tool is not a magical end-snapper--it will still be subjected to the same imperfections as the old bezier tool. If you're having trouble with snapping the end within specific constraints, then use a multiplier to change the speed ever so slightly until the slider fits. That, or reconsider where you want the slider to go.
Any questions?