I designed my own little dev board for the STM32F103VE7, which has an internal serial bootloader, though I wanted to put a proper DFU on it. I tried using the Maple bootloader modified slightly however it's driver is hopelessly out of whack, and I think the DFU code on it is dated and modified. I have been looking everywhere for a DFU bootloader that will work on this chip using standard STM32 DFU loader, but not having much luck, if anyone knows I would appreciate some help, thanks!