This results in slider placement including "excess" length, where the
curve is not applied to the placed path. This is generally not what we
want.
I considered adding a bool parameter (or enum) to change the
floor/rounding mode, but on further examination I think this is what we
always expect from this function.
If the same ruleset assembly was present more than once in the current
AppDomain, the game would crash. We recently saw this in Rider EAP9.
While this behaviour may change going forward, this is a good safety
measure regardless.