I am quite aware that it is approach speed discussion and also, that 1(+F) makes a huge difference and is not a very good example. No need to argue with RWU.
As you do fly the A321 you also know that at 89t the S speed is 220 kt and flaps would auto-retract at 210, so you are flying
as designed 10 below S speed with slats only - and it is completely normal. Same applies when passing S speed to clean up, again you are flying below green dot with no LE or TE devices at all (I hope I am correct to assume that you would claim it is incorrect to fly below green dot in clean, just like you say CF-2 is required to go below S speed).
As far as the books go:
FCTM Ch2 Intermediate Approach / DECELERATION AND CONFIGURATION CHANGE
A speed below the manoeuvring speed of the present
configuration may be selected provided it is above VLS.
FCOM 3.04.10 p2
S speed definiton:
In approach, used as a target speed when the aircraft is in CONF 1 ..... Equal to about 1,22 to 1,24 Vs in clean configuration.
F speed definition:
In approach, used as a target speed when the aircraft is in CONF 2 or CONF 3. .... Equal to about 1,18 to 1,22 Vs of CONF 1+F.
Now, everybody agrees that it is safe (nothing more than that) to fly V2 with engine out. V2 is:
Minimum value equal to 1,13 Vs for the corresponding configuration.
Hence my assumption that
lowest speed in config 1, Minimum speed with slats out. Below this speed you should have Flap 2 selected.
is indeed a very good practice but not a reqirement as per original Airbus design.