https://github.com/dewhisna/Arduino_STM32
Then, Steve has his own copy of Roger's core:This branch is 5 commits ahead, 102 commits behind rogerclarkmelbourne:master.
https://github.com/stevstrong/Arduino_STM32/
So, I took a look at Roger's current download from github and it does incorporate the I2C changes.This branch is 279 commits ahead, 10 commits behind rogerclarkmelbourne:master.
But, IMO, if you are beyond the 'hobby' stage of STM32 on ArduinoIDE, then the Official Corporate Core is a more sensible approach to computing with the STM32.