@olvido, and all the followers of this build thread.
Good News! Mojave 10.14.4 install OK with one minor surprise which was overcome with MultiBeast config install and reboot. Even the Thunderbolt 1 to Firewire 800 works. So, let's get started...
Warning! Make sure your graphics card is Metal compatible, and, if it's a Nvidia graphics card, you will not be able to update to Mojave as Nvidia has not released drivers for Mojave. (Nvidia and Apple must be having "get along issues".) However, you can run older Nvidia GTX 760 & 770 graphics cards with Apple's native graphic drivers. This why Thunderball now has an EVGA GTX 760.
Backup your latest macOS build (see next step).
(Optional) I decided to backup my High Sierra and install Mojave over High Sierra. If you are doing a fresh install, you can skip the next steps.
Run latest MultiBeast for High Sierra > full configuration like you did when you installed High Sierra; this will insure you have the latest Clover, drivers and config.plist patches.
Reboot and make a complete backup using Carbon Copy Cloner or SuperDuper; since the backup programs don't copy your EFI partition, you'll have to do the following:
Mount the EFI partition of your High Sierra disk and copy the EFI folder to the Desktop;
Eject the EFI partition and mount the EFI partition of your backup disk;
Make sure there is nothing in the backup disk's EFI partition; trash it if there is;
Copy the EFI folder from your Desktop to the backup disk's EFI partition.
Reboot into your BIOS, select the backup disk as your boot disk, save your change and boot into the backup disk.
If you were able to boot and get to the Desktop of the backup desk, you have good backup (test a few apps, too).
Reboot into your BIOS and select the High Sierra disk from which you made a backup as your boot disk, save your change boot into the High Sierra disk onto which you're going to install Mojave.
Try a few apps to make sure your High Sierra installation is running OK.
One more task before making the UniBeast for Mojave Installation USB thumb drive; update Clover using the MultiBeast for Mojave to get the latest Clover:
Quick Start > UEFI Boot Mode <--- just this configuration option
Install
Reboot
Download Mojave and make the Mojave UniBeast Installation USB thumb drive per the
tonymacx86 guide; BTW, I used a USB 3 thumb drive in Rear Panel's USB 3 port under the Ethernet port. UniBeast now supports using a USB 3 port on the Rear Panel.
Boot into the BIOS and select the Installation USB thumb drive (UEFI version) as your boot drive, save your BIOS choice and boot to the Clover Boot Screen.
At the Clover Boot Screen, select the Install macOS Mojave (external) icon (should be on the far left of the Clover Boot Screen).
As the installation proceeds, it will reboot several times. Clover knows which partition (icon) to boot from so sit back and watch. It will take ~20 minutes.
On the last reboot, there won't be any automatic Clover selection - just click on disk icon onto which you just install Mojave;
CAUTION! As you boot onto your Mojave Desktop, the macOS will ask you to log into iCloud. Don't do it yet...wait until after you install the MultiBeast configuration and reboot.
Now that you're at the Desktop, let's run MultiBeast for Mojave with the following configuration choices (
for AMD graphics cards):
Quick Start > UEFI Boot Mode
Drivers > Audio > AppleALC
(Optional) Drivers > Misc > FakeSMC Plugins
(Optional) Drivers > Misc > FakeSMC HWMonitor Application
Drivers > Network > Intel > AppleIntelE1000e <--- Use the latest version
Drivers > USB > 7/8/9 Series USB Support
Drivers > USB > USBInjectAll
Drivers > USB > Remove XHCI USB Port Limit <--- Adds patch to remove XHCI USB Port Limit
Build <--- To see your full configuration
Note: the MultiBeast default System Definition is iMac14,2. I recommend you use the iMac14,2 SysDef for your installation and to get Mojave up and running. You can change it later if need be.
Install
Don't reboot, yet.
(Fresh installers can skip this step.) When MultiBeast installation is done, open the /your Mojave disk/Library/Extensions/ folder. Move the Codec Commander kext to the trash and empty the trash. (It's not needed any more since we're using the AppleALC kext for audio.)
Reboot into the BIOS, select the Mojave disk as your boot drive, save your BIOS choice, boot to the Clover Boot Screen and select your Mojave disk.
Upon reaching the Desktop, now you can log into iCloud.
You now should be fully installed and ready to update your apps to the Mojave versions.
BTW, the minor surprise for me was the 1024 by 720 resolution for the Desktop until I ran MultiBeast. That hadn't happened since Snow Leopard 10.6.
Note: I will update the OP in the next day or two.