I only glanced at the new Lionel catalogue on their website, but aren't the LC+2.0 steamers in the new Lionel catalogue roughly equivalent to MTH Railking steamers?
My recollection is that the new LC+2.0 steamers navigate 031 curves as do most, if not all, MTH Railking steamers.
I agree with you regarding Lionel Visionline and Legacy. It is rare for a Legacy steamer to navigate 031 curves, and I have never seen a Visionline steamer that does.