It is not.  Only IRS and OH.  My concern is that the initial client letter contained this language:

Your 2019 Ohio Individual Income Tax Return will be electronically filed with the State of Ohio. No tax
is payable with the filing of this return. The refund of $106 will be directly deposited into your bank
account.
Your 2019 New Knoxville School District Income Tax Return (Form SD-100) will be electronically filed with the State of Ohio. There is a balance due of $527.
Mail your Ohio Form SD-40P on or before July 15, 2020 and make the check payable to "School District Income Tax", write the tax year and the last four digits of your social security number on the check and mail: (and gave the address).

I e-filed, but the acceptance letter only included the usual Federal and State acceptance confirmation. There was no mention of SD-100, and there doesn't appear to be any additional form information in the filing history.  Nor do I have an option to efile anything else. I was having the client mail a check to them anyway; I guess I should just have her mail a paper form to be sure. It's a small town; they'll figure it out!