The hash you make from trim has a limited area that has trichomes. Just because it's trim so the hash you make from a whole ounce of bud, trim ect. will have more volume of trichomes to harvent for good hash.

You can get more then one round out of full bud too. If you are going to use full oz of say swag then run it through once but save the working bag and refreeze the weed in the bag. (but not in your working bag that may damage the screen). You can run a second round and still get some hash out if it. Not the same quality as the first round but still all the same it's hash and it works too.

Does that answer your Q?