Instructions for Form 1040 state:
Because Form 2210 is complicated, you can leave line 23 blank and the IRS will figure the penalty and send you a bill. We won't charge you interest on the penalty if you pay by the date specified on the bill.
I know I should have been paying estimated taxes after reading Publication 505 (but didn't realize until now), but am I correct in my understanding that I can really just leave line 23 blank and the IRS will figure it out for me and bill me at no additional cost? Sounds too good to be true.