Well power losses are not linear (which would mean constant efficiency), a large proportion are conduction losses (I^2 x R), but you can see from my graphs (I should redo them with my new setup) that efficiency points aren’t linear either, but especially I think it’s the temperature increase that greatly increases power losses at high currents and tanks the efficiency, because running simulations without temperature modelisation gives a fairly straight efficiency curve.
Anyhow the Emisar boost driver efficiency is lower than that according to Hank’s measurements :
Which isn’t surprising since the inductor is smaller.
Edit : Vout is also higher.