IMO Either pipe makes little difference when using the EFI inlet which is a terrible inlet full stop (just look at it! lol), if you are worried about optimal flow you would choose another inlet and pipework accordingly

As for old looms, I wouldn't recommend using one, I never do... But if people want the plug and play option that's their choice and at least using an OFAM ECU makes fault finding it faster
I have a car in at the moment that's been EFI converted using OFAC and the loom is a right mess, I've spent a good few hours just diagnosing and repairing it... In fact this is why the car is with me, the customer couldn't get it to run right after the conversion! lol

Being stuck in the past thinking MS is just poorly built home made management doesn't help anyone, same as flogging the dead Cossie management horse... Times change, things move on, you have to move with them!