TMTLOGIC gave informations in April 2018 about the developpement of the Symbiface III card (see CPCWiki source too) :
- USB mass storage device FAT32, tested with an speed of 700Kb/sec, seen as drive D
- USB wireless mouse
- 512 KB RAM
- RTC (not compatible with the SF2 RTC) and a battery
- OLED display
The final choice of the features isnt frozen, you can propose other features on CPCWiki.