It is probably worth repeating the observation made by someone else, earlier in this thread, that most JMT SoBo hikers mail too much food to Muir Trail Ranch and end up leaving a lot of it in the "free barrel". (It's an actual barrel at Vermillion, a bunch of plastic tubs at MTR.) Early in the season the NoBo PCT hikers (most of whom seem to be both poor and hungry) will take this surplus food from the free barrel -- so the early-season SoBo JMT food surplus doesn't create too much of a problem for the staff at MTR.
But by this time in the season, there aren't enough hungry/poor NoBo PCT hikers still passing MTR to absorb all the extra food left by the SoBo JMT'rs. The MTR staff starts to get burdened by way too much surplus food left behind. They have to truck it (ancient German army vehicle) 5 miles over god-awful terrain and then boat it across the lake. They are nice enough to donate it to a homeless shelter, but it makes a lot of work for them.
Early in the season, it is probably a fine strategy to guess high on the amount of food you ship to yourself at MTR because if you abandon some of it in the early part of the season, the plentiful NoBo PCT folks will eagerly take it. But late in the season (roughly from here on out), we start to hugely outnumber the PCT folks and you are therefore probably better off under-estimating your needs. If you realize that you need more food than you shipped to yourself, you will find plenty of stuff in the free barrel.
The other problem for the MTR staff is the repackaging problem. It's really not fair to them to have to dispose of your surplus packaging material if you want to ship in one packaging material and then use different packaging in your bearcan. I'd try wherever possible to ship in the same packaging you plan to use ontrail. Or plan to carry both sets of packaging material with you as you leave MTR.
MTR is a major resource to us, since it is the southernmost convenient supply spot. We really aren't a key part of their business (mostly they cater to high-end groups who stay for a week) and we want them to like us. Not to mention their role in emergencies.
John Curran Ladd
1616 Castro Street
San Francisco, CA 94114-3707