any idea which group of Primitive Baptists are passionate about calling it an ordinance?
I don't recall it ever being presented as an ordinance here in E. Central KY, and I'm familiar with the churches of four surrounding counties. From the church at Lexington:
"9. We believe that baptism and the Lord’s supper are the ordinances of the church established by Jesus Christ and that true believers are the only fit subjects for baptism, immersion being the only proper mode. (Matthew 28:19; Luke 22:19-20; 1 Corinthians 11:24-25)
10. We believe that as our Lord and Savior washed His disciples’ feet, we ought to wash one another’s feet. (John 13:4-17; 1 Timothy 5:10)"