Specifically, the OP means noncash charitable deductions, since the cash category doesn't have a software issue.  But it is impressive to have 40% of your client base already completed (those without K1s or investment income of course) who still benefit more by itemizing than the standard deduction.

I'm only at 3% of my client base done, the ones who just have W2s, etc, standard deduction, really basic stuff right now.  Homeowners, self-employed, investment clients I'll see in March. Guess I have time to think about the logistics of another comment, that on the 50% AGI limit for noncash/carryover: 

I can see taxpayers generous with cash donations year after year, etc, but super-large noncash donations, doesn't someone run out of things to donate, year after year?  Unless they're shopaholics, and constantly buying stuff and turning around and donating?  I wouldn't give them personal advice for that!, but for my clients I advise (or 'teach them' to borrow a phrase) to adjust any prepayments/withholding so their refund is small, or even a small balance.  With the goal not to have a large refund, it also makes early filing not as important for them, and not stressful for a tax preparer having 40% of client base in just the first few days!