It doesn't need to be mentioned. That was the purpose in the tactic. The first attack was to bait a deflection if it did not strike, and that's precisely what happened.

From the way it was written, there was no real distinction between actions, and it seemed like you were simply double-referencing, which led me to believe that there were two separate timestamps. Firstly aerogel is hyper-present due to it being primarily air-based, and air is everywhere. He did not enchant it, he altered its physical properties using magic, which is closer to transmutation than enchanting. He also is not 'enchanting' Ishtalle. He's simply re-casting a previous spell with her as its target and Corban is capable of casting quite quickly even when he hasn't already used a spell, so we can assume he's casting at least double that speed when it comes to the ability that states he can cast them again. 

And why should I not be allowed to logically amp up a material if its under my control and I understand its ins and outs? What does it being 'synthetic' have anything to do with it? Should earth not be allowed to become harder? Water can't become hotter? And I don't believe you should be the one to gauge what my aerogel can take when it was summoned specifically to deal with the spell, a spell corban already knows and has already seen. Again, I think my aerogel defense is fine.

I wasn't aware of the gravity because I wasn't told. I specifically asked about the gravity portion of the spell earlier, and you said you weren't using it, even though you had also said you were still using other runes that would involve gravity. I took this to mean you were locking that ability regardless for whatever reason. So my not dealing with it in my post is because of that.

Edit: If you are still not satisfied, then we can consult Innue. I've lain my defenses and you your arguments. 

Edit 2: I also have a defence for the gravity argument. The disjunction was splitting apart the beam, which also means getting rid of a large chunk of its energy, which includes mass(gravity). So I actually think it splitting the beam around corban is entirely possible. 

Note: The aerogel and disjunction are being casted at once, not separately.