This church is found in the More Light affirming network of churches, although it doesn't state that affiliation on its website.
Their wedding page has a picture of what appears to be a same-sex marriage.
Its "Our Mission" page affirms sexual orientation, but not specifically gender identity.
The Letter of Thanks and Hope says "I hope that St. Mark continues to pursue understanding and respect for the transgender community. We can help the world know that God created people in many different ways, and that includes all people regardless of gender identity." This statement implies welcome but does not specify that the church affirms transgender people.
Thus, its score is Unclear: Affirming.