I use Lacerte, but this may help you.  I had two new S-Corps this year.  Startup costs, no revenue.

I aggregate the startup costs and enter the amount in the depreciation screen as an amortizable asset with no in-service date.  I'll add that in next year's software when business ops actually start, probably this next year.

That way I've captured the info for amortization in future years, which I think is the more appropriate treatment, and haven't messed with the P&L / NOL's, etc.