Just tried cross flashing a rom to my ZL, BeanStalk 4.4, I had to remove the kernel and modify the updater script, I used the kernel from the CM11 build that's up for the ZL, and the rom works but the screen won't fully turn off, it'll just go black but not off and brightness control doesn't work. Wonder if it'd be possible to include the required files for both the Z and ZL screens...
Current: Xperia ZL C6506 + CM11 w/ Tap2Wake
Previous: Galaxy Exhibit II 4G w/ CM11