Easier, yes.
Desirable, yes.
Not implemented because, quote Installation of Kicksecure on a USB
Why not just flash a persistent Kicksecure image to USB? - Such an image has not been developed yet due to complex technical challenges. Note that due to these complex challenges, almost no other Linux distributions offer such functionality either. To circumvent this, a “detour” through flashing a Kicksecure ISO is required to run the Kicksecure installer.