The whole firmware team are working on resolving the I2C issues - it’s our top priority, and we very much hope a solution is available soon.
Just to give you an insight into what we are dealing with, there are in fact bugs in the silicon of the STM32F205 that we are working around, so not all the issues are under our direct control, but we of course will do what we can to work around these. Our goal is for I2C to work for all devices where they work on the Core and other platforms.
Thanks for your patience so far and for bearing with us.