In Rouslan's teardown of the 305, he claims to have found the source of the hiss as 400khz power supply parasitics leaking in to the analog input because of PCB layout. He mentions that a star grounding scheme would alleviate this compared to the ground plane/pour. If this is the case, achieving a hiss free product (in the case of JBL) would not add any extra cost to the product.
With that said, it's unlikely all budget active monitors are committing the same problem but it's intuitively tempting to infer it with Kali's because it's the same engineer for both products. When one looks at all kinds of cheap audio products like wireless headphones, bluetooth speakers, and <30$ stereo amplifiers that don't exhibit hiss, it makes one wonder WHY THE F budget actives can't also be hiss free.