I tend to erase co-planer with this type of method…
def erase_coplaner(edges)
# erase hidden or coplaner but avoid others
edges.each do |e|
next if e.deleted?
e.hidden = false if e.hidden?
e.soft = false if e.soft?
e.smooth = false if e.smooth?
e.find_faces if e.faces.length == 0
e.erase! if e.faces.length == 2 && e.faces[0].normal.dot(e.faces[1].normal).abs > 0.9999999999999
end
end #erase_coplaner
john