I read through the testimony and was disappointed.
Initial thoughts: I'm disappointed for at least these reasons:
1. it says there are errorists "out there" but does not name nor cite them;
2. it puts forward many "errors" without proving that there actually are people within the circle of confessionally conservative Reformed and Presbyterian churches who hold to those specific "errors";
3. it puts forward the questionable distinction between "the invisible church" and "the visible church" as if it were fact;
4. it suggests that to reject the doctrine of "covenant of works" is an error;
5. it holds that the covenant of grace is established with the elect;
6. it says that the covenant of grace was made with Christ;
7. it denies that the covenant has conditions;
8. it is unclear about what, if anything, happens at baptism.
After I read the testimony, I thankfully reread Jelle Faber's American Secession Theologians on Covenant and Baptism.