+Saboteur-6 12U2 is your go to punish for most super punishable stuff, though you'll have to settle for less damage or bounce cancel for other punishes that require longer range.
I think his optimal midscreen damage with DF1 without MB divekick or some swag trait combo from 12U2 is, 12U2, D2~BF3, 12~DF1. Look for that nice moment where their legs are high in the air for the 12~DF1. That said, against some smaller hit box characters you might just want to do 12U2, 12U2, 12DF1 like +Batdaddy08 said or 12U2, D2~BF3, 212 or 21~BF3.
But you can also bounce cancel using B2 and Standing 3 using F3 for beefy damage. So something like 3~FFMB, 3~BF3, 3~BF3. This is good to know for stuff that standing 1 won't punish with the range it has.
Note that DF1 has a lot more advantage on hit then BF3 and is a hard knockdown, though won't leave you as close midscreen.
Also you can punish some stuff with divekick, which is good if you want that full combo damage with meter.