Late quarterly contributions shown on Schedule SB

[TJM]

Does anyone have a worksheet showing how to discount contributions made back to the beginning of the plan year where there are missed quarterlies.  I know we need to add 5% penalty to the effective interest rate on payments that should have been made as of the quarterly due date to the end of the plan year.  My question is on Schedule SB line 19c, is it ok for the discounted contributions (with the effective interest rate and penalty rate where applicable) to  be less than the MRC as of the beginning of the plan year?

[figure 8]

The 5% penalty applies from the date(s) of the applicable contribution(s) to the date(s) of the applicable quarterly date(s).

If the 19c discounted contributed is less than the MRC as of the val date, then there is a funding deficiency with excise tax due on the deficiency. It's "OK" to file an SB like this, but the funding deficiency would need to be appropriately addressed.