The answer appears to be yes.  While researching the Financial Management Regulation (FMR), DoDI 7000.14, I did not find anything prohibiting the use of O&M, I did stumble upon the following document:

[Note that the aforementioned form could not be attached and was e-mailed directly to the AAP POC]

DEPARTMENT OF DEFENSE ,DD 1414, BASE FOR REPROGRAMMING ACTIONS

DIVISION C OF PUBLIC LAW 115-141, DEPARTMENT OF DEFENSE

APPROPRIATIONS ACT, 2018

APPROVED: MARCH 23, 2018

EFFECTIVE: OCTOBER 1, 2017

Note that the Appropriation Account Title is Operation and Maintenance, Army (OMA) and one of the reductions is FFRDC.  The unclassified document showed a reduction of $1.8M in FFRDC funding. The obvious implication is that OMA can be used to fund FFRDCs.

We always recommend consulting with your local comptroller chain of command and legal office before taking action.