I did some research and found that a QMAC can be used to correct the ACP test up to the extent that the match exceeds the greater of 100% of deferral, 5% of compensation or 2x the Representative Contribution Rate.
New Question: Assuming a plan already contributes a matching contribution, is the 100% or 5% limits based on the QMAC calculation only, or the matching contribution plus the additional QMAC?