When a parent is receiving child support to pay for all direct expenses, the other parent's share is essentially relieved.  So, if you are in charge of direct expenses and receive the additional EPT amount, that is what it's supposed to help pay for.  The concept of the higher earning parent paying more of their share is already being corrected as part of the calculation.  So, to answer your question, I believe you would have to pay the entire amount with your child support.  Keep in mind that the child support amount you receive is only your ex's portion.  You must add to that your half to be able to see how much you might be spending.

Payments for direct expenses are not a blank check though.  Everything must be agreed by the parent.  An unwritten rule is that if the parents can't agree, then the parent desiring the activity is the one who pays for it.

I might also note that if you work a second job to make ends meet, the court should not be considering that income.  If the job was taken after the dissolution of the marriage, the court should not consider that income for child support purposes.

The court is required to use each parent's most current income for child support calculations.  Typically if a parent has lost their job, the other parent asks the court to make them pay child support as if they still had the old job (or which ever one pays more).  This is called imputing income.  However, if the loss of your job was not voluntary and you simply cannot find a job that makes the same wage, then that should be the end of it - until you find a higher paying job.  It's an endless cycle of going after your income, so I guess you should get used to that.  Just keep in mind that you're not the only one who needs to prove their income.  Both parents have rights.  If you're providing your income and W2's, the other parent should be doing the exact same thing.  In shared residency cases, the income of both parents is very important.

If you were unaware, you can always subpoena your ex's income.  This can be done without an attorney.  Sometimes this is necessary if they refuse to give you pay stubs.