You look to be in the early stage of your harvest window from the pics, though I personally like to see a little more amber in there. Don't strictly go by breeder timetables, they tend to run on the early side and a lot depends on when you call your plant "in flower", most call it a bit early. Flushing itself is a debatable topic as you have probably picked up from here and other sources. Harvest flushing isn't the same as flushing to treat nutrient toxicities or lockout, it's just normal "watering" without nutrients. Big misconception I see out there is not flushing soil, that only holds true with super soil, aka living soil, since you aren't adding nutrients to the medium but instead allowing the microbiom to supply nutritional needs. If you use chemical fertilizer though, you most certainly should- soil holds onto these nutrients longer than any other medium. I always recommend following the advise of your chosen nutrient line, I know General Hydroponics includes a flush week on their feed schedules.