'04 V70 2.5T- PEM relocate? Harness needed or not?

[cypilot]

Searching for an answer;
Our '04 V70, steel tank, 2.5T PEM died. No big deal- we've had a pile of V70's inc R's, so the PEM is a known headache. But...this is the first one that the PEM hasn't been relocated already. So, steel fuel tank..this PEM was on top of the tank on the passenger side. Weird clip/bracket thing held it in place- I hit it with a flat bladed screwdriver and it came loose.
Got it removed and unplugged no issue, full of corrosion of course. New one arrives tomorrow.
Question:
I'd like to relocate the PEM to inside the car- truly don't care where, as this is my college-son's car, driven very rarely.

My question is this:
Do I need the OEM relocate harness, or can I just pull the existing harness through the fuel pump access and place the PEM in the rear seat area somewhere it has room to expel heat? I know the relocate harness is long enough to put in the spare tire area- I'm fine with under the rear seats or even on the vertical part of the rear right footwell.
Keep in mind, this is a steel tank, so there's an access port on the passenger side only, unlike the plastic tank cars which have 2. I've put in several steel tank fuel pumps over the years, so I'm comfortable puling the harness through the access cover into the passenger compartment.

[cn90]

I simply replaced with a good PEM in the 2004 V70.

Same location. Don't overthink it.

I used a newer PEM (all interchangeable) ending with ---225.
Bought on eBay with unit removed from a newer model such as 2012 etc.

[cn90]

More info on PEMs...

viewtopic.php?t=87748

[erikv11]

If the harness can reach, it works. Why not just give it a try? Getting the PEM into the car is a good move.