I haven't added a mount point for internal storage based on my personal preference and few technical reasons.
-As a linux user myself, the whole MTP protocol is a complete mess. It's much better to have a single mount point for usb-storage.
-Partition layout in Blade III. Internal storage is actually just emulated storage on data partition. When you wipe data and install a new ROM, you will also lose all personal data that you had on the internal storage.
-ZTE has done it wrong in their stock ROMs. This means that also their windows usb-drivers are done wrong. ZTE has reversed the mount points and internal storage is displayed as sdcard and vice versa.
Sdcards are extremely cheap. Just get one when you're lucky enough to have a device that supports it. It really doesn't make that much of a difference if you can utilize that 1-2GB (at best) on internal storage. It's a 2,5GB partition that should house all of your apps, app data, dalvik cache, etc and on top of that your personal files. Imo it's much better that you don't have to worry about running out of space for apps than to clutter the data partition with your personal files and start moving apps to your sdcard.