As @sjrcpa said, "I agree with the others - I prefer not to do this quarterly calculation crap for a small business."

I think it's all very 20th-Century.  Tax practitioner as secular guru requiring constant communication when really you should just be running your business.  Maybe a quarterly email in the first year, to check on whether the initial plan is still viable.   And whether it's time to elect S Corp status.  Bill at an hourly rate if it gets to be more than 10 minutes, more than twice a year.