Sync a base build to a live character

Is your feature request related to a problem? Please describe.
I am usually trying to look at ways to improve an existing character and it can be frustrating to have to reset everything by importing from scratch each time.

Describe the solution you'd like
I would like to be able to pair one set of tree/items/skills as a single variation that if you imported it from a live character can update again. And then additional trees/items/skill variations can be branched off that to experiment with changes.

Describe alternatives you've considered
Current process is to create a new build from a fresh import each time and then re-add any planned changes (ie chase uniques, gg end items)

Additional context
You can already have multiple trees and skill sets. Trying them together under a single grouping would be a great start. This is a very large set of features that would all go into the functionality described so multiple smaller feature requests would be easier if I'm not the only one that would want this

No files, tests, or entry points are named in the issue. First define the smallest grouping, update, and branching scope and its acceptance criteria; done would mean a grouped tree, item, and skill variation can be refreshed from a live character and used as a base for additional variations.