Flare cue appears around 20 ft, AT shall be off before, but if you forget it goes to idle at 20 ft as well :-), since DH is 50ft, should not be an issue...
commercial brochure : https://das.falconjet.com/i/cp_files/HGS%20and%20EFVS.pdf
https://www.rockwellcollins.com/~/media/Files/Unsecure/Products/Product%20Brochures/Displays/Head%20up%20displays/HGS-3500%20White-Paper.aspx