Tea Caffeine Hot

So the knobs for tea caffeine levels are variety of tea (ignoring not-tea such as chamomile tea), how abused the leaves are, water temperature, and brew time. Maximum caffeine? Black tea, powdered leaves, boiling water, long and insulated brew. Minimum caffeine? White tea, minimal leaf processing (basically they dried the leaves a little), low water temperature (somewhere below 85C or so), quick brew time. There will also be flavor differences: white tea can be pretty subtle, while powdering the leaves and long brew times will extract more bitters.