My 3-Phase Home-based ESS-Backup System in the South of the Netherlands

Yes, would be better to have none load.

During switching from position 1 to 2 you will pass the “0“ position where power is off.
And switching from “0“ to the 2 position is the same as you would do with a 3 phase circuit beaker (they guarantee switch event to be withing a few ms for all contacts).