Alloha: sorry mate,but you are one of many that developed a 'personal' SOP.
The 20000' is a limitation for flaps ,not a recomendation.Just read L.10.5 regarding this.
Regarding flap usage you should read the FCTM,where it says that 'selecting the next flap setting should be initiated when reaching the maneuver speed for the existing flap position'.
Actually,most european airports will give you a short level segment,in order to extend flap.This doesn't increase noise,cause when you'll come level you'll select lower speed,flaps,then lower speed again,flaps....so,no need to increase power.
The 3NM/250-210 IAS speed reduction is given for level flight.
Also,flaps 1-10 will provide NO increase in drag,only lift.It,s in the charts and the FCTM.
Also,flying with F5 at 220 kts will put you very close to the 230 kts limit for flap (on classic) And what if you encounter turbulance?
I don't see a problem in remaining high with speed ,cause I don't do it.When I start feeling unhappy with it I just inform ATC that I start reducing speed to...,that's all.I never got a refusal on this...No need for aerobatics at low level..
Brgds