I went back, reexamined D2, utilized it a bit more online and I still feel eh about it, but now, I at least understand how it functions at all ranges. AA crossovers and around one char length away is the optional range for Jax's D2.
I'll explain, I was in a scenario last night were I was playing a Cassie player. She would use her guns to bait me midscreen/her max jump range, and go for a jump 1. My first instinct is to just walk back and punish her jump-in attempt, but Jax's back movement is free in this game, so once I get in her max jump range its really difficult to walk in&out to bait a whiffed jump attack. So I think about my options like dashing back/neutral jumping 1 but eventually I go with making the read to look out for her Jump 1 and prepare a AA as a counter to this problem, because I do have a 6f D2 in my arsenal so why not use it?
Anyway, She jumped, and my brain registered it slightly before she hit her max height. I threw out my D2, and it came out, but it got stuffed. This happened numerous times in our set until I said fuck it, and started throwing bf4 on a pure read which had pretty good success because this Cassie player was pretty predictable when she jumped.
After this set, I went into training mode and set the bot to Cassie jip 1 from different distances around midscreen to see if online was making D2 inconsistent, and I found out some properties about the attack I didn't know before. Jax's D2 is great at the range were Jax is around a char length away, but at the range of Cassie max jip 1 is when it gets inconsistent. From now on I decided to AA with bf4 at midscreen and d2 for crossovers and at a char length away. I am still not sure what to do about jump kicks at a close range though because D2 seems to trade or get stuffed by them.
Also, does anyone feel like Jax's walkspeed/floaty jump will be a huge issue for him as the game evolves? I heard Tyrant is approaching the char from a defensive stand point now, and I think its solely because of the chars movement/jump being butt.