Spacial Transition
Spacial Transition is, in essence, a pseudo-teleportation ability that moves the caster from Point A to Point B. However, in this universe, genuine teleportation doesn't actually exist. Spacial Transition is, instead, a rapid-transferrance of matter between two points. However, the only difference is the speed at which the action is performed (and the strain resulting from said speed.) That is, the object still has to physically move between these two points, just at a rapidly accelerated speed. This makes the use of the spells under this category extremely dangerous, as any wrong move can kill you.
General Statistics
Success Rate
The success rate of spacial transition is extraordinarily low, even when cast by a seasoned sorcerer. If a skilled sorcerer jumps a mere 10 meters, the chances of success are low. However, if you double that distance to 20 meters, it drops to single digits. If you were to attempt to transition to the furthest distance your voice (spell) could reach, the odds of success would be less than 1%.
Complications
A failure to cast the spell could cause every cell in your body to boil, completely destroying it. Because the spell is a transfer of matter between two points, and not a literal teleportation, you're also subject to any obstacles in your path. For example, if there's a wall between you and your destination point, there's a good chance you'd die from force of impact, as you'd be hitting that wall at tremendous speed. This isn't to mention that moving at such high speed causes atmospheric friction, superheating your body. This raises the possibility of your body simply not being abe to withstand the strain of the transfer, and dying instanty.
With all of these things taken into account, it's no wonder that Spacial Transitions are reserved for situations where you're pretty much dead anyway, and have nothing to lose.
In Silence Magic
In Volume 7, the transitioning used by Celestial Dolls is described by the Demon King (himself a doll) to be removing one from the timeline momentarily. He insists that this must be done swiftly, and last no more than a few seconds.
However, given that dolls are able to move through solid structures, such as appearing in rooms with no entrances, it becomes clear that their version of spacial transitioning is fundamentally different from the type used by sorcerers. Perhaps it shares some properties, but the barrier of physical objects ceases to be an issue. This may infer that Silence Magic transitioning is genuine teleportation, whereas Spacial Transition is not.