This is the trade-off when using cascaded shadows. You get a set distance for the cascades to be spread across. You have use the additional settings for Num Dynamic Shadow Cascades, to which you can have 10 but you have to manually type that in and it is more expensive to use, and Distribution Exponent which adjusts how the cascades are distributed across the cascades.
For dynamic shadowing you cannot have perfect shadows across all cascades. These are distance based and will reduce in quality the further away you are so as to keep performance from being that of an offline renderer.
Clever idea about using dual directional lights here, but I suspect you’ll pay for it in the end with performance. It’s not intended to use more than one in the scene at a time. Something to keep an eye out for!