Maybe someone can tell me if I should or can defol...

hey there Amnezia, you're right about the cal mag deficiency specifically it's magnesium deficiency , when you have such an intense light schedule you need more magnesium and that's why you're seeing deficiency , so adding magnesium works , but the leafs wont fully recover meaning they wont become green again but it should stop spreading immediately or almost immediately, if it keeps spreading you have light stress in a bad way so you need to dial down the light schedule (you dont want to hear that i know) . At this stage in flower for autos, if you have just started to LST you will hurt your yield, for some reason autos get a bit stiffer than other kinds of plants. same thing with defoliation, your plant is not that bushy, and with minimal airflow it will be fine, defol will shock your plant and may even trigger it to concentrate on making leafs . Hope this helps ! 🚀