Here is a Spell Mastery ability researched in our Saga. In general we set the threshold for researching them low, though you could increase it in your game.
Connection Mastery (OR Minor Breakthrough 15)
Sources of Insight: -
Relevant Spells: Arcane Connection range travel/teleport spells
Stipulations: Some way of binding the memory of a location, such as the Art of Memory Ability or CrMe spells. Knowing an improved form of creating Arcane Connections (such as the faster creation/create multiple per season refinement) can help.
Effect: Can learn the Spell Mastery ability "Connection Mastery" for spells which that target a location by Arcane Connection.
Connection Mastery ability
Spell Mastery ability
For spells that target a location by Arcane Connection, you have developed innate Arcane Connections that can be used as the target of the Mastered Spell. You may attune one location per point of Mastery. One attuned location can be dropped each time your Spell Mastery increases, allowing you to change your bond locations. (Normally used with teleport spells)
EDIT: If you drop a location, you can assign it to a new location at the same time. Saying something like "One attuned location can be changed..." would have been more clear.