I prefer to flush each time and do a courtesy flush as required.
Don't overfeed, simple at that. If you see something in the leaves, adjust as you normally would.
If you have a hankering to see a fade, it won't hurt your plant in any noticeable way, either. With soilless (says coco coir in your diary) i wouldn't be lazy with the fertilization for longer than 5 days. If you are religious with 10% runoff or more, the substrate won't build up a high EC charge - a good thing throughout grow. Also, don't "flush" it. Just do water-only and minimize runoff, unlike the typical SOP for soilless. Leaching off nutes in runoff would shorten that ~5 day estimate.
From video: i'd give the lusher plants 5 days and the one with paler leaves by comparison 3 days. But, that video isn't so great. you can see much better, so just make a logical conclusion in this regard to adjust how long you think you can give water-only.
food for thought -- do they flush the soil around plants outdoors approaching harvest? No, because that would be absurd. Probablay ruin the next years crop too, lol, flushing away all the good stuff.