The 50K goes into the assets, no matter what you do with the COB and/or PB.
The "angles" are numerous. Many actuaries (me among them) will say, "Keep your balance(s) as long as you can, until you are better off to use and/or waive", but that is not a unanimous opinion.
In this case, the big picture is that the plan is underfunded. Therefore, the plan needs cash from some source. BTW, an AFTAP of 85% is overstated if you are talking about plan termination liability.