RX8Club.com - Engine dies suddenly after running for 20 minutes

Hey guys,
Before I start, I've done my research and have tested and thrown some parts at the car at the time of this post, and if this post doesn't get some results - I'll be taking the car to my Rotary specialist.

Background -
Before this issue began, my engine was rebuilt by a very well known rotary builder, and the installation was handled by a pretty reputable specialist in the area. The current mileage on the engine is about 3000 km (2000 miles).
Modifications that may be relevant to the issue -
It has an AEM intake, the engine was ported during the rebuild (not bridged), the previous owner replaced the entire exhaust system with headers, custom midpipe with high flow cat.
The fuel pump that was on the car had 19,000 km on it. Plugs were changed with the engine (3000 km) and the coils and leads are at 18,000 km
I've cleaned the MAF, TB,

Issue -
The issue began with the car refusing to start after shutting it off after a 20-minute drive. The car would not even start when I attempted to push start it. It was cranking absolutely fine. I attempted to de-flood both using the accel pedal method, as well as removing the fuel pump fuse. It made no difference - the sound of the cranking didn't change either. I opened up the rear seat, I could *feel* the fuel pump priming when I turned the key. Interestingly, I did get the car to fire a bit while cranking by spraying some 'Start ya bastard' into the car ('aerolized fuel' - might be native to 'Straya)

I left the car there, returned after 3 hours with tools - the car started up on its own.:Eyecrazy:

While driving the car back home, after about 15 minutes of running - the car died again. I was going down a hill, about 3 seconds after I took my foot off the pedal, the tach went from about 4k rpm to 0, and the engine died (in gear! )

The car was towed home after this.
I confirmed that the car dies after about 20 minutes of running - you can see the car struggling to stay alive a little if you look at my prosport oil pressure gauge, it fluctuates as if the engine load is changing, and then it dies. RPM stays at idle during this though - doesn't move at all.

I took apart the fuel pump assembly and replaced the OEM unit with a DW200, melted the pop-off cap etc.
The issue is still present.
After the car dies - opening the fuel cap (to relieve pressure inside the fuel tank) and then disconnecting the fuel pump discharge line doesn't spew fuel everywhere. This was the case both before and after replacing the pump - which makes me think this is an electrical issue? I've tried swapping the FUEL and CIRCUIT relays- doesn't change anything.

I measured the resistance Fuel Pump Resistor at cold and while warm, there wasn't much of a difference, but it was around 2.2 ohms (Interestingly, my multimeter reads about 20 ohms initially, then it dropped to 2.2 and stays there. Every time)
I have a new resistor arriving Thursday, other than that I can think of no other issues than
Fuel pump failed, starved the engine and damaged it - low compression
Issue with rebuild - low compression
Injectors wired or installed the wrong way around? Does anyone have any knowledge on this issue?
Or a horrifying electrical gremlin.

I guess I'm just looking for any other thoughts on what the issue is?
Apologies for the long write-up.

TL;DR - Replaced fuel pump, the car still dies when warm. It's not the relays, it might be the resistor.