The way you've defined your <rule> blocks, however, doesn't match what you want to do. Your <rule> blocks apply the color and stroke_color "grey" to specific links, but change nothing else.
I've attached an example in which different <rule> blocks are used to change the geometry: bezier_radius and crest.
For your conditions, you want to use
condition = between(chr1A,chr1B)
to apply to links between these two chromosomes.
Links for which <rule> block's condition(s) is/are true will be affected by the block. Otherwise, the data point is not affected but it is still drawn.
The bezier_radius_purity is influenced by the distance between link ends. See
It's a useful parameter if you have a large variety of links and want to visually separate them.
m