Monticello 1.6 will be all about truly atomic loading, thanks to SystemEditor. The atomic loader comes with every copy of Monticello 1.5, but is disabled by default. So this script just loads up MC 1.5, SystemEditor, and enables the atomic loader.
Note that this is beta level software, but I think it mostly works
There is no support for Traits yet, or for Tweak fields, so you won't be able to load Traits or Nile or parts of Omnibrowser with this enabled.
To use the stable loader, disable the preference monticello > useMonticelloAtomicLoader
Installer ss project: 'SystemEditor'; install: 'SystemEditor-Core'; install: 'SystemEditor-Squeak'. Preferences setPreference: #useMonticelloAtomicLoader toValue: true.