An i6 engine offered now would be great considering its the most suitable (ex. historical standpoint, and so on) and that its the last ideal ICE setup we'll get.

Yeah it'd be very fitting it they used and I6 before they really start going all electric.

It would to an extent, if the BMW sourced engine sounds too close to the BMW, it won't be as fitting.
I'm sure changes can be to ensure it won't happen in stock configuration.

One last run on going hard on V8 development would be nice. Not much longer from now, V8's will be gone forever!

I'd love to see that too, but sadly I don't think JLR is going to do it.

IMO...
It would be a great way to launch more Project 8 style vehicles.
Limited in quantity of course but no better way to end an era.

That's the only way I could see that actually happening. A limited run could also lead to some unique designs which would be a great send off.

Prior to that it might be best to have more SVR versions to get sales volume up.