- In perspective/user view, Isopoint selection is jumpy and almost
unusable, because the selection tolerance is zero. You have to hover
exactly over the curve to place the Isopoint.
In ortho views, it works conveniently.
Also, after task switching, snapping seems to somehow hang - although it
is off, Isopoints snap to Knots.
Repro: create a Curve, go to Isopoint component, switch to another task,
click on SI's title bar, and try to select an Isopoint exactly on the Curve.
After click-deselecting in the vp, it works again.
