Yep gioua u r correct it does depend alot on strains, and leaves left on increases weight but u gotta trim dry. That strain in the pic is the densest strain i grow and many things were done during flowering to increase mass like molasses.etc. It is a very solid chunky strain. I lose more then 90% on some strians depending on trimming techniques. Grape Krush loses alot if you trim it wet with a trim pro you kinda have to but if you screen it and dry fast omg.
I know many use products like gravity in flower. Seen many dry-rehydrate close to sale to stay away from mold. Some rehydrate just opening a lb in a wet basement you can gain a oz overnit with some strains, or use fresh bud.
The speed at which i dry also seems to effect the total numbers i am noticing.