Seeing that they nerfed several spells this way, I don't like this at all. The way I see it, this has been done to protect minions, but it reduces the wizard's damage output, which could lead to (more) combat grind. I'm going to ignore this change for my games.
Also, why didn't they just state that in general, walls and zones only deal damage once per round (or per turn, if you prefer) to a creature? That eliminates the ping-pong of death issue without having tonerfupdate multiple spells.
The Blood Mage got nerfed again? Oh dear. Destructive Salutation could have kept a stunned UENT plus the ongoing damage effect on a hit.![]()
Minions have heaps of problems anyway. A wizard can have area burst 2 damage effects from level 1 - at will and ally friendly. I have a Valorous Bard in the party. Adding minions makes the encounter easier, they are just nice pouches of temporary hit points. Virtually every class has a way to attack at lest 2 per turn. You should not consider the changes a protection for minions, they are not.
I agree with you on that the rule should be walls and zones only deal damage once per round/turn The changes to the Flaming Sphere make it an appalling daily.
Destructive Salutation was very strong but so are a lot of other spells. Stunning until end of encounter was always a joke with the changes to the saving throws. A daze effect on a level 19 daily for a wizard is just not strong enough to be wroth taking. They should have reduced the damage or remove the enemy only instead if they wanted to weaken it.
Come on WotC, balancing powers is OK but making powers useless just annoys the players!!!