I get the solar panels argument and sometimes leaving more leaf on works better but inside you get more light to bud sights so they grow better and better airflow when you remove some leaf depends on the strain and your grow but normally cutting off around 10% to 30% of the plants mass going into flowering means more buds and bigger buds
as for releasing the stored K, and even the stored N this is done in the last 2 to 4 weeks of flowering yellowing the leaves and such
I find it can make trimming harder if you over do it, but it helps more with airy buds to get them harder
I`ve fed the plant so it can grow leaves if I`m not going to use them for anything then I`d rather the plant sucked all the sugar out of them and I was left with a dry brown leaf to throw away than a healthy one
Roots can only do so much in a day but sucking up all the extra sugar from the plants leaves can get you an extra weeks growth in the last week or 2 normally seems worth it to me