Hi,
i have see STM32H7 board seems supported as i see h7 folder in the stm32 libopencm3 library.
I have buy the WeActStudio MiniSTM32H7 and if i can use libopencm3 for this board it will help me a lot :)
Did you have a simple blink exemple for stm32h7 family ?
Thanks for your lib i use it for years in my STM32F1/F4 projects.