Thanks Monstsa. That sounds like a great development. However, when I tried to install caja 1.18, it said it was missing a dependency of caja common 1.18. But, when I tried to install caja common 1.18, that in turn required another dependency. About three dependencies in, it simply refused to install it without giving a reason that was easy to understand.
So, for the moment, for inexperienced users, I would still recommend using pcmanfm to manage the desktop even if it is only used for that purpose alone and caja is installed alongside and used for all file manager activities.