Manx the important problem of the droop is that on a T1 at max landing weight the stall speed increased by 30 knots whilst take off flap of 10 degrees made an additional difference of 8 knots.
Add to that supposedly the stall speed increase was virtually instantaneous with droop retraction on the T1 whereas it is gradual with flap retraction.
The other marks of Trident had slotted droop which worked in a different way.
The relevance to the accident is that BEA had a unique noise abatement proceedure which saw the flap being selected up after take off leaving only one possible selection to change the stall speed by 30knots plus.