little white / off white / pale yellow spheres are eggs, removing them manually does help.
I think the moths look for existing eggs as a cue for where to lay them safely, so if you remove them early on it goes a log way. BT is also the best preventative as you know.
another tip- do not hang whole buds or branches to dry. if they are in bad shape, you will continue to lose bud to mold and pests. It is best to do an immediate trim right after harvest, and to gently cut the buds into their smallest possible individual pieces. This way you will have an efficient drying process, and you will be able to inspect the interior surface of the buds for hidden damage.
best of luck with your harvest, some years outdoor growing is practically a war of attrition haha. Just try to save what you can.