From the developers:
1. If you need to poll faster than the 12msec, this may be a bit difficult and still meet BLE timing.
2. As an alternative, you would need to use the BT Clock ( A very low level activity that will be associated with meeting BLE Timing) but you may not be able to meet BLE timing.
3. The BT Timer might get delayed because of you polling faster than 12msec
Hope this helps.
Thanks for checking with the developers. I believe 12msec will be absolutely fine - I just wanted to check I was running at the maximum rate possible and was using the best approach. Our application will be primarily based on polling various peripherals, as opposed to being interrupt driven.
Good luck on your project!