Late to the party, here, probably because I was just looking at syncing templates with a laptop.
The way I settled on was going to Aeon Timeline->Settings in the menus (I’m on a Mac).
From there, click the Custom Templates tab. Each template has an export link.
On the other system, go to the same place Aeon Timeline->Settings and use the import link to import the exported templates.
On a related note, I always get confused when creating a custom relationship. Does a Person Participate in an Event, or does an Event get a Participant who is a person?
Here’s how I keep that straight.
Consider an item type of Knitting Club and another item type of Person.
The name of a new relationship is a verb, or maybe an adverb. It isn’t a thing, it describes an effect of one item type on another. The relationship is a bridge between item types, named for what the relationship is.
So, let’s create troublemakers in the Relationship Types tab, found in the cog window.
The new relationship might be called Berserker. In the left column, check Knitting Club and on the right column click Person. A Knitting Club has a Berserker who is a Person.
The Inverse name could be Victimized.
In one direction, you have a Knitting Club with a Berserker who is a Person. In the other direction, you have a Person who Victimized a Knitting Club.
No harm intended for knitting clubs. Or berserkers. Trying to make progress against a wall of knitting needles can’t be easy.
The left hand column types have a thing comprised of right hand column types in the Relationship Types window. The “thing” is denoted by the relationship name.
Hope I have that right.