SimFactory could provide a command to display the usage information of the user's allocation on a machine. For example,
$ sim show-allocation Allocation: TG38372811 Total: 100000 Used: 10000 Used by <user>: 50000 Remaining: 90000
Some systems will not be able to provide all this information, and some will not have the concept of an allocation. The output should be easy to parse by scripts (e.g. for updating group web pages).