It literally makes no difference in efficiency unless you drive differently. Slower acceleration is a bit more efficient, but its really not a big deal generally. If the battery is warm, accelerating at halfish throttle is a very minor impact over accelerating super slow. Full throttle, and a bit near full, is definitely less efficient. But it only makes a difference for the few seconds you're accelerating. If you're constantly accelerating full throttle and then stopping, its going to be very noticeable. However, if you accelerate only occasionally and are mostly just cruising, it makes very little difference to the total trip.
The thing about "remapping your right foot" is a real thing, lol. I hardly ever drive my wifes X3 M40 anymore as I prefer my model 3... but when I do, I end up driving it like the proverbial "grandpa driving to church on sunday" because my foot is used to the "throttle" mapping in my model 3p. Its not like my wifes car is slow... its supposed to be 0=60 in like 4.6 seconds which USED to sound fast to me, lol.
Anyway, because I drive my model 3P like a civilized person instead of a hoonigan (most of the time, anyway lol... i DID spring for the P version for a reason, though ) whenever I drive any other vehicle, I always end up driving it slow, because "car acceleration" has been re mapped in my head to my car, so I press lighter, so every car other than my model 3p accelerates slower for me.