Excess contribution due to prefunding balance

Thanks in advance for help.  

2019 Funding Requirement $100k,

Carryover Balance $0

Prefunding balance $150k

Employer elects to apply $40k of PFB towards funding requirement, but later makes $80k contribution (let's forget about discounting for this)

This results in excess contribution due to credit balance of $20k.  Does employer have option to add back the excess contribution to PFB, adjusted for actual return on assets?

Thanks.

See lines 11b(2) and 38b of the Schedule SB