the easiest i think if you don't mind using commands would be to unresearch the 2 last levels, and again research the one before:
example if the last level you did is lvl 7:
/c game.forces.player.technologies['dw-factory-beacon-7'].researched=false
/c game.forces.player.technologies['dw-factory-beacon-6'].researched=false
/c game.forces.player.technologies['dw-factory-beacon-6'].researched=true
this should put you back in level 6 beacon.
If you remove it with editor then research a new level, it should come back, but i'd save before doing that.
Related to the ON/OFF: yes, i agree, I just need to find a correct way to do that as the game doesn't allow beacon to be inactive.