Hello Nicholas Soldner,
If you have a project which is written in KSDK 1.0 you should migrate your project to KSDK 1.2.
Since new version KSDK 1.2. we recommend to use this version because of support new MCUs (KSDK 1.0. has support only for 5 boards, after that you need standalone versions), added peripheral support (FLEXIO, XBAR, FLEXBUS....).
Also you can test new examples (power_manager_hal_demo, power_manager_rtos_demo) and and driver examples (cmp, pit, i2c, gpio.. ) created for your MCU.
In difference with KSDK 1.0, KSDK 1.2 devices directory contains device specific (not CMSIS compliant) header files which provide direct access to the Kinetis MCU peripheral registers.
I´m attaching you the guide for SDK Migration created for IAR IDE.
I hope this helps,
Iva