Case in point: I set my counterspell on a caster, and then this caster decides to use a cantrip or do a staff melee attack, while the OTHER caster in the same fight goes for a fireball. How is that any better than the dumb toggle system we have currently, in the end?
First of all... Why the hell would you only plan counterspell VS a single caster if there are 2 of them ? Maybe I could just target both of them and tell the game to trigger the reaction against lvl 3+ spells ? (because for this specific spells its something we should be able to manage. At least we just manage the variation once and then we'll probably use the same during all our playtrough)
Maybe one of them is a boss ? If the boss is attacking first I'll target both. If not I think I'll still only target the boss... What would you do if the minion is casting a lightning arrows first ? yes ? no ? You should probably have clicked no because the boss is now casting a fireball... Hopefully I've only chosen to target the boss !
Giving specific exemples to make your point more valuable doesn't make sense. We all know that pops up give you more control. But in the end I don't care of having FULL control because it doesn't mean that you are bound to make the best choices.
I just want to have fun with my class features/spells and I had more fun casting one more things during my turn in BG3 than I ever have when I clicked "yes" in Solasta.
To Tuco's point, if you select both spellcasters, but one uses Magic Missile while the other uses Fireball, if you do presets, and the Magic Missile mage goes first, you waste Counterspell on Magic Missile. Then the Fireball mage sends his Fireball at you. You have to make sure that you set it not only to trigger on the Leader but also on certain spells. You have to have very specific presets.
Another example. You set your Counterspell to Level 3 or higher spells and you target 2 Mages and 1 Cleric. The cleric goes first and casts Beacon of Hope. You Counterspell it. Mage 2 goes and casts Fireball. Mage 3 goes and casts Fireball. You COULD have stopped at least 1 of the 2 Fireballs, but you actually stopped the Beacon of Hope spell because you chose Level 3 or higher spells, 2 Mages and 1 Cleric.
But, what if the Cleric actually cast a spell that you did want to block, like Mass Healing Word to heal up a bunch of his allies near him? Well, then you'd still want to make sure you had him included in your list of enemies. You wouldn't want to just have the mages. You'd want to stop that healing.
The point is, the presets might require too many nuances to make them effective. That's the flaw with the system. For Counterspell, you'd have to probably pick the select spells you'd want to actually counter. You wouldn't want to counter Beacon of Hope or Major Image, but you'd want to counter Melf's Minute Meteors, and Fireball, and Lightning Bolt, and maybe Pulse Wave, and... The list would just go on and on.