The "Variable Compression Turbo" screen is my usual screen. At engine start, the indicated compression ratio shows low (i.e. high into the 'power' range). After 1 to 2 minutes, it shifts to maximum compression (bottom of 'eco' range). Is it better for the engine to wait for that shift before putting it in gear and driving? The owner's manual just says to let the engine run at least 30 seconds before driving.

Driving gently until the temp gauge comes up is always better than prolonged idling. That's true for any engine, not just VC's.

The question is where is the boundaries between 'sufficient' and 'prolonged' idling are. Driving gently is good advice until you have to figure out how to gently merge on the freeway whose on ramp, going up hill, is .5 miles from your house. Most of the time I'm going a different direction so it's not an issue.

My first car was my dad's big Buick with a 7 liter carbureted V8. You could drive it several miles before the coolant temp. gauge began moving up. Modern tiny-engined cars warm up very fast in comparison, but it's still usually at least a mile.

Same here. I usually let my '04 Altie idle about 2 minutes, a little longer if it's very cold, and I try not to punch it on the ramp. You can only do what circumstances allow.