Counterspelled Booming Blade

[Psyren]

You're skipping around a bit here.

You are making the case that fire and magical fire are not the same, and pointing to Spelljammer as support of this.

Correct, and that RAW is a data point that I'm ultimately using to support my ruling.

I am saying that in order to argue from RAW, the rules have to tell us explicitly that it does or doesn't do something. So your spelljammer example is fine, assuming someone is using spelljammer. But it doesn't do anything to support that magical fire doesn't shed light, as an example, because it doesn't speak to that. Saying "well they're different in this one way according to spelljammer" doesn't mean they are different in all the ways you might want them to be.

That's true, but again, the RAW is that the spell lasts for its duration unless otherwise stated. That is another data point that ultimately I'm using to support my ruling.

It is an interpretation to say that a spell with a duration cannot be impacted by another spell unless it explicitly says so. It is an interpretation that "protected" means "by a spell's duration".

Tidal Wave says it extinguishes unprotected flames. In order to go against that RAW, you have to interpret that spell durations are intrinsically tied to their effects (the Conjure line of spells don't seem to support this, also see Lesser Restoration and Blinding Smite from Diplomancer's example), then say that spell durations can't be impacted by other spells, and also say that spell effects are "protected" by virtue of being magical effects of a spell.

For the record, I'm not going against the extinguish line. I'm ruling that tidal wave extinguishes the flames and then they reappear immediately. That would satisfy both the Tidal Wave clause and the Wall of Fire duration by RAW. It wouldn't be particularly helpful for those folks who want Tidal Wave to defeat Wall of Fire of course.