If the K70 was supported in mcuxpresso, this issue might be a mute point. However, because NXP has not added the K70 into mcuxpresso as one of the supported processors and their only suggestion is to use KDS, well here is a KDS bug that needs fixing. Hopefully, they won't just ignore this.
The another bug is in the LCDC_LDD component for the TWR_K70 that comes with KDS. The HW cursor initialization tab has a box to allow blinking to be turned on and the "Blinking rate" to be set from 1 to 255. Turning blinking on works when the code is generated, but the blinking rate has no effect. The component uses the default value of 0xFF that is set at system reset. Changing the value manually indeed changes the Blinking rate so it is not a hardware issue but a component generation issue.