Silt strider routes should ideally have few elevation changes. When mapping out the silt strider route between Menaan and Arvud (image attached below), I noticed that there is no obstacle-free connection, but there are two potential connections that have one obstacle each. As the left path has fewer elevation changes overall, it is the more favourable route.
The obstacle that stands in its way is a rock arch that is too low to admit a silt strider. As it would take little effort to adjust its position to accommodate a silt strider, I think it might be worthwhile to do so.