Generally, if you ask IRS to keep your refund toward the next year's estimated payments, then they will apply the entire amount toward the first estimated payment. If it is more than is needed, then it will just have excess applied to the first payment. You can then reduce the remaining payments so that the total is still paid in while the income is being earned so you don't have an underpayment penalty in any quarter.
You can still pay an additional estimated payment amount if you wish, to be safe.
