Lugging and Shift points

[MK7german]

I have a 2016 Stage 2 E30 Fiesta ST, and I'm worried about whether or not I’m 'lugging' the engine. While the car is cold, I usually shift at 2,000 RPM and cruise around 1,250–1,500 RPM (typically 6th gear at 40 mph). I only use about 30–45% throttle to speed up, and I never accelerate heavily in 5th or 6th gear until I'm above 2,500 RPM. Additionally, I never accelerate if the engine feels like it’s shaking or struggling. Is this fine for the car, or should I change my habits?

 

[killer5280]

Don't lug it. Let it rev freely.
But don't run it hard until the oil gets up to temperature.