"when clearing the IRS has said we could start filing January 28th, 2021."

But that isn't true. The IRS didn't start accepting efiling until Feb 12. Sending something, doesn't mean it is accepted for processing. People sending early were Test Subjects, like dropping it off on the porch.

It's true that your software isn't fully updated and not all forms are out. Do you have people who got unemployment in 2020? You know MD just now voted to change their taxable treatment of it, and the Feds are considering a similar bill? How will your clients take it when they won't have as much taxes owed, but also they need to pay you for an amended return?

And with the TX disaster, keep watching for a changed filing deadline, as happened last year.