Alright just got to disc 3. For the most part everything seems pretty polished. Here are a few minor things I noticed though, in case you're interested in working more on this patch at a later date:
Aeris does not appear alongside your other party member in two scenes that I've found-
a. In Lucretia's cave when you take Vincent after obtaining the sub.
b. During the scene after the Corel Huge Materia event, the conversation where you acquire Ultima.
Other minor cosmetic oddities -
a. During the scene where you are being attacked by the Schizo Left in Gaea's cliff, Aeris appears but stands still with her back to the camera while your other two characters are "interacting" with the scene (looking around, getting in their fight pose, etc). This might be intentional, but given how well she interacts in other scenes I figured it was probably an oversight.
b. When deciding whom to give the black materia to later in Gaea's cliff, her dialog seems to be triggered incorrectly. She right off makes a comment about following Jenova (I'm assuming this is the dialog she is supposed to switch to after you've given the black materia to someone). She only makes a comment regarding the black materia when you talk to Vincent prior to giving it to someone, during which she is off-screen, leading me to assume that something is working incorrectly here.
c. After she moves to the top deck of the airship, her dialog is triggered simply by approaching her, and she does not turn to face you when she says it. Normally, you have to hit <confirm> to trigger dialog with your other members on the airship (including with Aeris before she moves up top), and they turn to face you. I've accidentally triggered the dialog multiple times just by moving too close to her. Again, might be intentional, but I wanted to let you know in case it wasn't.
d. Aeris does not appear anywhere on the airship when you are docked at the Northern crater. The scene on the top deck changes, so that's probably why.
Anyway, it's been a blast, although I'd like to see more dialog from her in future versions
. Thanks again!