The various tax software tools don't often adjust their penalty calculations for disaster relief. I usually find I need to manually calculate any penalties.

I use the software tool "TaxInterest" sometimes.

Other times I let Lacerte build the whole penalty, tell the client that I know it's too high, but I'd rather they get a check in the mail than a bill from the IRS, so to go ahead and pay it for now, and the IRS will figure it out and refund them. Ymmv.