Got a lot of useful info off this site so here's a possible contribution.
Another relay, Britax 35 amp four pin and 25/30 amp five pin sealed with resistor.
Available in Aus and NZ at least from any auto electrical shop.
Tried OEX and number five failed after 2000km.
Currently have Britax 5 pin in number 1 and four pin in 2 and 5 only 300km to date
No hesitation under 3000rpm even though you shouldn't but you do sometimes in traffic.
Was occasional hesitation before OEX failed and difficult starting a couple of times.
Engine just stopped at 120 km/hr when it failed.
Carry spares, I had one, easy fix.
Starts well and consistently hot or cold and runs superbly again.
Original fuel pump between the cylinders, starts hot at 32 deg C ambient.