The bonnet vents on my XFR over the years have let water in and soaked the inner wool/material bonnet cover/heat shield.
It's sagged and come apart around the holes, and I'm finding it hard to source a new one.
Would it be a problem if I just removed it all together?

Not sure but with an XFR I think I would be worried about engine heat on the paint?

I mean the vents are functional for a reason! The engine runs pretty hot.
On my XJR the heat just pours out of the hood vents.
.
.
.

That padding on the hood is really there for sound deadening since it is a luxury car.

Agreed.
I have been running my F-Type for over a year now with no engine cover and no bonnet mat/cover (no F-Type has ever had a bonnet mat anyway) with zero vent or paint problems, and I know for a fact that the vents and the surrounding bonnet (hood) areas get quite hot.
The XF including XFR bonnet/hoot mat comes off fairly easily (I took it off my old XFR a couple of times to apply anti-rattle tape to the bonnet vents), about a dozen square clips which you push sideways and a two (maybe four?) scrivets in the middle.
One tip though - it will probably drop lots of dirt, dust and other crud all over your engine bay, so cover the engine bay first with a tarp, blanket, towels, whatever.

Mine has been off for about 2 Years with no issues, plenty of desert runs LA to Vegas, and this temp just last week in Palm Springs CA.




or about 49ºC.

Can any-one report if there's anymore sound created by the engine either inside or out the car when the covers been removed?

I get just a hint of supercharger whine.

ive had mine off for over a year. no heat issues, no mechanical issues.


the only benefit is a little bit more mechanical sounds and supercharger whine

More supercharger whine is only a good thing, it's far to quite on the XFR

I was thinking about taking off that but putting heat reflective tape on the bottom of the hood to protect the paint. Similar to this corvette.. I have wrapped my top mount intercooler on my Subaru with it and it made a big difference in heat soak.

one thing to (possibly) be cautious of....it might just be TOTAL coincidence with my car, but the heat started to make the coolant expansion tank crack and leak

The coolant tank is a maintenance item on Jaguars and Land Rovers. I replaced both of mine before they failed when I did the big coolant pipe replacement projects on both cars. So I wouldn't blame anything to do with the hood insulations for your cracking tank.

No issues here

Have to agree on the coolant tank. I just consider them wear items and it's common on almost every car if you keep it long enough.
After all this time it's hard to believe they can't improve this item especially on massively expensive $100K+ cars.
I mean I looked under the hood of a late model Shelby Mustang and they used an nice welded Aluminum tank. Man that would look sweet under the hood of my XJ!

What a GREAT looking XFR-S!! Can't believe they made it in a station wagon too. It's a shame they never imported that model into the states.
Cadillac tried the same thing with a CTS-V wagon that had a 6 speed manual transmission. But they just did not sell.
.
.
.