Perhaps some features can be programmed through JLR’s (SDD) Symptom Driven Diagnostic tool. I’ve had two X351’s & neither would close the sunroof with a global close. But my replacement has seat belt warning chimes in the back seat. (None of the other six jaguar I have owned have had that.) I use my XJL Portfolio for rideshare, and I have had passengers from other locales tell me that the laws in there home state may require everyone in the backseat to be belted so it could be a car that came from such a location was programmed locally to match those laws.

Just like I knew with my X350 you could program running lights* on or off with a unknown menu. (*Really just headlights without any other running lights turned on.) That seems standard with a lot of manufacturers, which explains why sometimes you see cars driving down the road with their headlights on but nothing else because their ‘running lights’ are on. (Yes, it does burn through the bulbs more quickly!)

The whole point of this is just because something works for you doesn’t mean it’s going to work for somebody else. Your car maybe programmed for wherever it came from.

 

I'm disappointed that the LEDs around the perimeter of the headlights aren't used as the DRLs instead of the full headlight. As you said, I thought of turning-on the DRLs with SDD, but it's not worth the price of headlight "bulb" replacements.
The same with my 2012 LR RR, it has perimeter LEDs that ring the headlights, but do nothing but accent the headlights when they're on for cosmetic purpose.
They could at least use these or the parking lights as DRLs.
I imagine a true "hack" could fit into the OEM code for the LCM, and change the DRL selection to power the LEDs or parking lights instead of the headlights; unless of course it's at the wiring and not LCM relays.

 

I think you have seen this? It does what your wanting to do and was posted a few times as "X351 Signature Light Hack".
It's a simple wiring change.
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would this wiring method work to connect say an illuminated grill badge directly into fuse box (02 fuse?) so it would stay lit with the ignition on?

 

Don't see why not? It powers the DRL 100% of the time the car is running so it should run your emblem too.
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