It is very easy to move nodes out of the canvas. You can just move nodes out of it to top or left.

As result:

• Nodes are not visible in the process preview
• After process reopen you can't see your nodes, you see empty process (if all process nodes out of the canvas area)
• At runtime nodes out of the canvas are not displayed
• After migration to old designer nodes also not visible, but after save/reopen you will see nodes gathered in one closes to the canvas border point.

Probably canvas borders shouldn't exist at all and nodes location should be recalculated automatically on save action. (as alternative expand canvas on the left/top and in this case move all nodes to created distance.