[karotte]

> 1. Does Horizon support an equivalent to the 'Variant Manager?'

No, but there's been some discussion on it: https://github.com/horizon-eda/horizon/pull/347#issuecomment...

> 2. In the docs it seems to mention submitting parts to the default pool. If people submit parts to the pool are there style guides somewhere?

There's https://github.com/horizon-eda/horizon-pool-convention, but that's still work in progress.

> 3. Is there a way to set paste mask expansion like is done in Altium?

Yes, you can set it globally in the board.