First press the rosin, then BHO the chips. Why use more butane than necessary? If you can still press rosin out, you don't need butane yet. Granted the yield would be low but what else are you going to do, throw the chips away? Has anybody ever ground the chips up and seen how much BHO they can get? Probably about 5% still in there. Whether it would be worth the butane idk, but could use a cheaper solvent. Wonder what happens if you extract with alcohol and then dissolve that greenish extract with butane. Would it dissolve the chlorophyll too or would it come out amber? Maybe you don't have to do the initial extraction with costly butane.