User blog comment:Wythagoras/Extension of SCG/@comment-5029411-20130809235135/@comment-1605058-20130810074426

I don't think so. From what I've heard Robertson Seymour theorem is provable in Pi11-CA0-BI, which limit is TFB ordinal, so Minor(n), which diagonalizes through this theorem and upper bounds SCG(n,n), probably has ordinal smaller than that.