If they at least had saving throws it'd be more in line, and the fact it breaks Concentration is frustrating.
Yeah, agreed, it'll be better than what we have now, but it'll still be an item that allows the attacker three tries at forcing the other to lose concentration:
1. when the fire bottle causes damage to the other by passing the AC check
2. when it creates a surface that the other has to roll a Dex saving throw against to prevent from taking damage.
3. when it fails the above two and has to roll a Con saving throw to keep the spell running.
Such an item will be more in line with DnD's ecosystem, but it's still very overpowered. One molotov cocktail from Larian's homebrew has three chances at breaking a caster's concentration.
