I'm a coco noob but here are my thoughts.
Most cal mag has a far to high ratio of calcium to magnesium IMO. Especially under LED (speculation) i feel it creates most of the cal mag issues we see. High amounts of calcium can also affect uptake of other nutrients as we increase the cal mag to fix what we see as a cal mag issue. Specifically potassium, phosphorus, nitrogen, magnesium and many micros. I combat this by using half dose of
calmag and adding 1 gram per gal of epsom salt to bring th calcium and magnesium ratios to a more favorable level. I like Ca to be about half the ppm of my potassium and magnesium to be about half the ppm of calcium.
As for coco I feed at a volume thats 5% of the pot its in and look for 10-20% of that to come out as runoff volume. I adjust my feed frequency based on the runoff. If getting less than 10% i increase the frequency and water more often. This helps keep stable ratios, ppm and PH in the media.
I also use VPD as a guide for humidity and make sure I have good airflow through the plants. I like to keep room temps with LED about 80-85f with the lights on as this gives me my desired leaf temps of about 77-80f because I run co2. If not then maybe a few degrees cooler like 80-82f for 75-77f leaf temps. Then adjust the humidity.
Its important to co keep coco saturated to keep stable parameters in the rootzone.