I have now operated my petrol IG on an extended trip of 8,000 kms (approx 5,000 Mississippi units) with my long range tank.
Love love love the extended range in remote Australia.
However, remote Australia is also very hot. Drove in temps above 40C (that’s about 104 freedom units), for 3 days. I had already worked out that the aux pump transfers fuel at about 2.2 L/min (about 0.6 Grandpa units). However, on day 2, I commenced my second transfer for the day, at about 41C, the transfer rate dropped substantially. So much so, I thought the pump had failed. Now I start sweating about fuel range, and how much I had actually transferred before I thought the pump had failed.
Next morning with temps in the mid 20’s, the aux pump transferred normally again. I observed the same scenario again on day 3.
So, in my experience, the petrol LRA system does not transfer well (maybe not at all) in high temperatures.