Installed Mojave 10.14.2 on APFS RAID 0 and encountered the problems described in this post and was able to overcome them. Let me try to pass on what I learned.
Code:
gpt create /dev/disk9
gpt add -b 40 -s 409600 -i 1 -t efi /dev/disk9
gpt show /dev/disk9
start size index contents
0 1 PMBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
409640 1997375415
1997785055 32 Sec GPT table
1997785087 1 Sec GPT header
On the second gpt add command make sure to use -b 409640 not 409600 or you'll get an error message "not enough space left on device". Use the second number listed (in my case 1997375415) to as your -s parameter to add the remaining free space.
Code:
gpt add -b 409640 -s 1997375415 -i 2 -t apfs /dev/disk9
Once you get this far you should be able to run the Mojave installer, select the RAID volume, get all the way through without hitting the preboot error. It will then reboot, install a bunch more, and then you'll get all the way almost to the end and it will error out with:
To anyone who gets this far, yes, this can be done from the installer. Once the error message dialog appears asking you to reboot, you can access the menubar along the top right (country code and keyboard). Once you've accessed the top menubar you'll need to mount the volume read/write. This can be done from the command line (somehow) but I did it by selecting Utilities => Disk Utility selecting the drive that represented the RAID set, clicked mount. Once the volume is mounted Quit Disk Utility.
Next go to back to the top menu bar => Utilities => Terminal.
Code:
cd /Volumes/Macintosh\ RAID/usr/standalone/
mv bootcaches.plist bootcaches.plist.bak
No pesky SIP in the Mojave installer thankfully.
Quit Terminal
You'll be taken back to the error screen, offering for you to reboot, do so, you should then reboot into the Mojave setup screen!
