I used the Data Asset approach, setting chunk ID 1 for fast-follow and leaving the rest with the default ID for the base installation.
Chunks get saved in “Saved\StagedBuilds[PlatformName][ProjectName]\Content\Paks” when you build the app, and then you are supposed to move them to
“Build/Android/gradle/assetpacks/fast-follow/[assetpackname]/src/main/assets” so that they get packaged into the ABB next time you generate it.
As I’ve said before, I’ve never got it actually running, but paks where generated and integrated into de ABB.