Its automatic, since that is what toggle is ...
Either its on, or its off ... but nothing in between ... you loose tactical option to decide if you wish to spend Ki point on this specific action in this specific situation ... either you had it on before and then you simply loose your Ki point automaticly no matter if you wish that or not ... or you had it off before and then you simply cannot use this option no matter if you wish that or not.
That is exactly what i hate with burning passion, on Hellish Rebuke ...
Im fightint Bugbear and spend my extremely precious Spell Slot on Warlock ... obviously hoping that this Bugbear will hit me and will get HARD revenge ... just to be hit by some stupid lowly common goblin (sometimes even with last single HP) and give him 2d10 damage as reaction ... in other words i just spend half my spellslots i had at disposal to give 1damage and waste up to 19. -_-
There is simply no way for you to plan this in any way, except killing every weak creature and then start focusing to Strong one with everything you have at your disposal ... and that is also bullshit, since its much faster, better and more effective to first kill the Bugbear with regular attacks and then mess with lowly insignificant goblins that give hardly 1/3 of his damage.
This is something that is acceptable from amateur moder ...
But certainly not from "proffesionals". :-/
