macOS High Sierra Patched USB Issue's

[TheGamer3399]

Hello ya'll,

I recently got a 2008 Mac Pro at a E-Waste collection center for € 100, before I hear "It is broken". It isn't and works with its current install of Snow Leopard & Random Windows 10 HDD.
Since Apple doesn't officially support this specific device anymore I used dosdude1's patcher.
What I noticed is the Mac Pro refuses to detect the flash drive created on my Early 2015 MacBook Air running High Sierra.
After trying multiple USB Flashdrives I decided to see if the MBA would find the USB & boot into the installer, sure enough it detects it (While holding alt right after POST) and boots into it.
Installation is still not verified since I'm not replacing my current install on that machine, only fully updated Mac I have.

Here is the TL;DR

I have tried multiple USB Flashdrives with a patched High Sierra on it, all of them using the GUID Partition Table & HFS+ Journaled.
All the ones I created work on another more recent Mac, but fail to even be recognized on my Mac Pro.
Anyone who can help me out?

- TheGamer3399, Sfekke. (I made this account years ago, name leaves a lot to be desired.)

EDIT :
My personal guess is that this is a software problem and not something wrong with the Mac Pro's hardware.
What I did before attempting this install, I traced back all my steps.
Fully clean the machine before attempting this clean install, added an NVIDIA Quadro FX1800 (It works under Snow Leopard). What I didn't add is more RAM, but it seems like it has an extra 4GB's right of the getgo.

What I also tried is running on the default 4x 512MB RAM, 1 HDD (WD Green Made in +-2012) with the AMD GPU that came with the thing. (It displays heavy artifact meaning it is on its last legs.

 

[h9826790]

It can be much harder than you can expect to boot from a USB flash drive on a cMP. TBH, connect your cMP HDD to the MacBook Air, install HS from there is much easier, and then you can move the HDD back to the cMP.

 

[TheGamer3399]

It can be much harder than you can expect to boot from a USB flash drive on a cMP. TBH, connect your cMP HDD to the MacBook Air, install HS from there is much easier, and then you can move the HDD back to the cMP.

Thanks for the advice, one problem being is that my macbook air doesn't like the installer of the patched HS.
Its video glitches out after getting through the first dialog screen. (Only tried this once, so I'll retry)

I'll retry again and connect an empty HDD over USB, I do vaguely remember Mac OS X (Back then) not playing nice with USB hard drive enclosures and getting installed onto them.
Quite a while back I did manage to get a PowerMac G5 installed over USB using this USB (with different version of Mac OS X but still)

Anyhow I'll give that another shot, keeping ya'll posted