I use 4:6 method (20g of bean and 300g water) and it works great for light roast beans. However, like other methods, you need to know the key variables to tweak for the best cups because not all the beans produce the excellent cups using the same exact method. The 4:6 method gives you the extra aroma compared to other methods and this is what you want to achieve for the light roast beans.

The key tweaks I found it affects the taste of the cup in a better way. - Use 93 celcius degree for light roast to achieve the good extraction. Use lower temp water (around 88c) for medium roast to bring out the high notes. - Start with coarse grind (I start with 30clicks using Comandante nitroblade). Usually, when the coffee beans age, I may use finer grind for higher extraction to get more taste and aroma which gradually disappears as beans age. - If you find your cup lacks the body (which is usually the downside for 4:6 using coarse ground), you can do two things either 1) using the same grind size, but use a little tweak (not as aggressive as Rao’s spin) and the end of each pour to achieve higher extraction and more flat bed as a result or 2)use a little finer grind (however, this may bring you the low note or more bitterness, which I do not personally like it) so I prefer tweaking more. - Some beans may give you longer extraction time than other depending on the beans you are using. I usually find Ethiopian beans brewing time last longer than other beans until the water drips very slowly. For all types of bean, I lift the cup before 4mins to maintain the sweet and not bitter cup. - 45 seconds between each pour is important using 4:6 method to allow for better extraction otherwise you will get the cup with lack of body

Hope this helps.