Off of the crossup f+3 I got ji3, 223~ex lift, ji2, 223 for 401 damage.
I looked at those combos, and found that (In trait) F3 (Crossup or not), F2 xx Close Overcharged Lantern, B13 xx MB Lantern's Might, J3, 223 does 422. Obviously the one you put is best for traitless, which is great to know, but I find if you do b13 xx trait xx Lantern's Might, you have just a little bit of juice left to squeeze out the combo I put above for a bit more damage.
Also, I'm not sure if I'm doing something way wrong, but I've seen many players doing these setups:
b+1,3~trait~lift, 223, forward dash, neutral jump, 3
b+1,3~EX lift, b+3, ji2, 223, forward dash, neutral jump, 3
In my testing, these are both smoke and mirrors setups. I must be doing something way wrong with my timing?... maybe someone can help me? In my testing, I could 100% just backdash out of the neutral jump on reaction every time... there was no mixup there at all.
I thought this too, wondering if perhaps all of the setups so far have been too related to IGAU and not adjusting to the larger options for the defender in I2. Since I had the day off, I figured I'd do a little investigating.
This was the best I could find that seemed to cover all bases. I chose Robin because he has a really fast rising wakeup as well as some other slightly invincible ones that move him forward. Notice how those all whiff because of the wacky way GL lifts his body during J1. Look at the inputs, too, and notice how you have to block vs. how it looks visually. If someone blocks that on their first try, I'll eat my hat.
Of course there's more than one way to wakeup, which I also looked into.
This is with short getup and using B1. Notice Robin is not able to use his 6 frame D1 as he gets counter hit pretty easily. It's not shown, but backdashing gets hit as well. F3, unfortunately, is so slow that there are a multitude of options you can do to escape. Conditioning is important!
Then there's long getup.
Notice here, F3 gets some more juice. The only ways to really make it miss are to reversal MB B3 or dash forward. Obviously you can remove one option with a meterless opponent, but forward dashing is still a problem for some characters with fast dashes. Enter...
B1 hits so fast on a long getup that you can barely see your character even begin to move before they are hit. As you can see in the video, this easily stops almost every form of movement, especially that MB B3 and forward dash that will stop F3. Again, condition and you can get your best possible option.
So there's that, a pretty comprehensive setup that is not so easy to block to begin with and provides a lot of covers for both types of delayed getup. Keep in mind this is just an option; I still think if you have the read, just walk up and go for crossup or not F3 since you get a ton of damage and great positioning on block from it. But if you want to test your opponent and see what they can do, I think this is a pretty low risk way to do it.
Another thing worth mentioning is that this was just vs. Robin, who I feel has a mixture of all the different types of wakeup options. There may very well be some wakeups that completely avoid this setup that I might have missed, so I'll leave that for you to find.