I refers saveBeforePreview implementation in Phobos to implement saveAll feature.

saveBeforePreviewAction(), saveBeforeClose() is already implemented in Phobos.

saveAllDocumentsBeforeBuild()/saveAllBeforeInstallAction().. have almost same flow as saveBeforePreviewAction().

Why do you think saveAllDocumentsBeforeBuild() is not needed while saveBeforePreviewAction() is needed in Phobos?

And which file do you expect saveAllBeforeInstallAction() is implemented in except Phobos?