I was perusing trough the parts catalog offered by JLCPCB for their assembly service and found this awesome micro controller STM32H750VB it is quite an upgrade over the good old F407 part. It runs newer Cortex-M7 ARM core, it has double precision FP unit and can run at sweet 480MHz. Best of all it was mostly pin compatible with the F407. I had to re-route one side of the pins, but it was fairly quick.
The only down side is that the build-in flash is a bit limited – 128KB, but I think I can work with that. I’ll order some boards with that processor once the factories in China are bully back in business.
The updated design is on my github page in the “new_cpu” branch.