The current backups only happen on saving, but if a layout crashes and saving has been forgotten, a lot of effort is required to get back the changes. An autosave every 15 or 30 minutes would prevent that, and might even make hunting bugs slightly easier eg the crash occurs 3 minutes after this autosave. Autosave would also be useful when testing a layout, but not necessarily making changes. It could be left running unsupervised and if autosave is selected and a train does something it shouldn't, then the autosaved versions can be looked at for the reason without the need to go back to the start time of the layout.