Beta will be save compatible, but with the full release some balance changes may conflict, so to be safe, it's always better to wait for full release (or start a new campaign).
Full release on steam will be on Wednesday.
This Friday,, it will be released for Patrons Beta and on Monday,, for Public Beta. The name of this update is Order and Mayhem, and its main focuses are Bretonnia, Chaos, and the new DLC factions. Grown and grown to a point where it’s really massive, 16 pages of changelog and tons of changes. So we did, and in that time the update has grown. It’s a special time in the year when a new, major update is out for SFO: Grimhammer II! But this update is special it was ready 2 months ago, but the community decided to wait for the DLC to release.