Absolutely, I’m in business and have to do mine quarterly and supposed to send estimated prepayments. But because my wife and I file jointly I only send it at the end of the year. They have never mentioned it so I’m going to keep doing it. Like you say... Why loan them money interest free when it can be my business working capital.
Quarterly estimates are not prepayments, they are a substitute for witholding. They are required by law. I'm surprised the IRS isn't hitting you with interest and penalties.