The bootloader supports transparently low-medium and high density devices without recompilation. The tkg-hid-bootloader doesn't use any ST libraries, but only CMSIS SDK.

Secure USB DFU1.1 bootloader for STM32 with STM32F4x1xE target fully compatible to STM32duino and PlatformIO - rbm78bln/STM32duino-bootloader_stm32f411-blackpill ...