Thanks for the inputs, gents. really appreciate it.
Obviously there is a difference between climb speeds (v2, Vfri and Vfto) and approach speeds due to thrust, but the question really is what is the slowest airspeed you can fly on descend/approach/hold without getting a "check speed" call or FDM event? Both Boeing and Airbus are pretty clear on minimum clean speeds: Bombardier not so much.
Bombardier does publish max endurance speeds for the hold which are a knot or two above Vfto, and thereby much lower than the 160/170/180 knots mentioned here. (let's leave icing out of it for the moment while agreeing that it adds a good 20-25kts to any speed except v2 up to 1000'agl.)
For a given weight, say 27 tonns (54k lbs) Vfto is 152 and published clean holding speed is 154. A company that has a minimum clean speed 15-20 knots higher would need to correct their fuel burn in the hold accordingly.
Or, to put it another way, is there a good argument for allowing the hold (with it's level flight and varying bank abgles) to be flown at Vfto but placing a higher restriction on the final approach which by it's very nature (unless finishing with a circling maneuver) is very limited in bank?
Appreciate any further input.