Default PURL settings for maintaing context in Spaces are confusing

When using the Spaces project, I got very confused by the behaviour around PURL maintaining the context of the current space - when I navigated outside the space, the context seemed to stay. I eventually found the correct issue and approach for this, but only after posting my own issue. The way to solve this is to set purl on menu items so that it does not "maintain" the persistent url.

I think that this is partly because the documentation doesn't make this obvious enough, and partly because the default settings are confusing. I suspect that for most users of the Spaces module, they will configure the menus so that the PURL context is maintained for the features menu, and disabled for all others. Any other settings will tend to make a site that feels broken, or else would need significant customisation to make them make sense. I would therefore suggest that the defaults for the items in menus be set as I just described:

• Features: PURL > maintain
• Other menus: PURL > discard

Does this make sense, or does it conflict with the PURL module itself given that it is no longer being used only with Spaces?