You want to give strait water last two weeks so the plant can use up its nutrient stores, if everything goes well. Buds are sinks though and only take in nutrients and never release them, so if you have over fertilized you can never flush that out, and will make for harsh smoke and probably not taste very good. If your plants are still pretty green at the end I’d say flush. If there hurting for nutes, dropping alot of leaves keep giving nutes. There’s also 2 types of flush. One is just giving strait water at the end of cycle. The other is literally Flushing the soil with copious amounts of water, mostly to remove salt build ups, or to try and correct nutrition.
A few things I’d like to point out is everyone grows differently, have different set ups, use different nutes. It’s hard to say do this, not that because of it. Also each strain might require more or less nutrients. Alot of different factors go into nutrient uptake, if it’s a new strain it will probably take atleast a run to learn how the plant will do in your set up.