My thoughts after some various lab junk-
U3 seems really really quite good and possibly the combo ender of choice for shenanigans(or maybe there's a crap ton better). The nice thing is that it's special cancelable but leaves the opponent in air while the special comes out. Various junk i've found off this(all old i'm assuming)
U3 then-
medium mine- If they don't quick rise/wakeup(for whatever reason...you can maybe train it) you can dash in and overhead for a nasty block situation. Likely blockable but not sure how easy it'll be for humans. Low hits first.
close mine- Seems pretty useless. Maybe to catch forward rolls?
Far mine- just far enough that if they don't do anything on wakeup, you can dash forward overhead, and if they block the overhead it'll push them into the low mine, or it can chase and pressure back rolls. In fact while i suck, both far and medium mine seem to space perfectly for an unblockable(for humans i think. Dummy can do it. will test later) if you use Jumping 3.
Beam- Mostly worthless, but it does catch some back roll to wakeup attack situations. Decent in the corner.
MB beam - catches damn near everything except not rolling, and probably some wakeup attacks.
Drone- might give a little more time than other setups to throw one and get in. Didn't mess with it too much.
MB drone- see above.
Staff shenanigans- Worth noting that these work best in the corner, but you can also staff cancel off of a hit 2, 1 for a slight mixup(nothing more than a gimmick). Not sure if it's worth going for off of U3 since they can likely read the staff charge and just wakeup attack out, but the 2,1 setup might be worth some extra damage.
lvl 1 straight- will combo.
Lvl 2 straight - if it hits, will lead to d1, corps charge in the corner...and that's about it as far as i could find.
Lvl 3 straight- 10% unblockable damage, kd, tons of pushback. Can't combo off of it.
Lvl 1 up- will combo
lvl 2 up- leads to combo's in the corner. The lvl 2 straight seems to only be able to be followed up with d1, but the lvl 2 up staff, in the corner, leads to 1, 1, 2 juggle at the very least. I'll leave it to better people to figure out what you can get off of it.
lvl 3 up- same as lvl 3 straight.
All of these can also be trait canceled to beat certain wakeups/setup.
So again, maybe some of this will help(i was beginning to think that sometimes lex should end in 2,1 and setup to keep them from getting wakeups in certain matchups), but again, didn't have time to check before posting, so sorry if none of it is new.