Thanks for the replies. The situation was that some who do children's catechism in my church were thinking of adopting the CGS philosophy because it appears to align with things they already did. They were also considering getting CGS certified.
They asked for opinions. My immediate response was that we didn't need certification. If the catechists wanted, they (and some others with education backgrounds) could read the books from the CGS originator over the summer and use what was agreed was good.
To me, Montessori seems to take one good thing and run with it; if there is "bad" it's mainly in the possible exclusion of other good things. If Montessori has theosophic influence, how does that reveal itself?
Compare Waldorf/Steiner education, which also focuses on experiential education, but its strange philosophy is evident even in earliest education.