I find this weird. Resource Manager has prefixes. Third-party addons like Bob's AMS and UBS have it. I would love it if XFMG had prefixes so I could use those for game selection in different genres, vs sub-categories making a long category selection prompt when uploading.
Because XFMG is still based on the original version that was adopted when Chris moved it from a personal 3rd party add-on to a 1st party when he got hired by XenForo years ago.
Like all the other 1st party add-ons.. they have been ignored for years for improvement. It's pretty much par fo the course with Xenfroro developers. It's not an area of current concern/interest for them so they continue to ignore it even though there are many areas it could be drastically improved. A simple example is their XFMG mirroring function. If the node has custom fields in use... XFMG totally ignores them and only imports the image, not the corresponding custom fields that may be directly related to the image.
XFMG, XFES and XFRM have many areas that they could be improved upon, but they are not a major concern of XenForo. As we say in East Texas (and other locales are similar), they are the bastard step children of XenForo.
It is simply another reason that Invision is considered as a full suite for a website and XenForo remains basically a forum.