I think you should offer a premium version of the Espruino IDE for $4.99 on the chrome store. This premium version would have support for the STM32 Nucleo and Discovery series boards with 256k or more. I would like support for the stm32F401RE specifically, but many of them would work well with Espruino.
I would buy the espruino, but I would need to solder some female headers on, and I would need to re-write code to work with my Arduino shields. This way way you get some money, and I don't need to buy another board when I already have 10 similar boards. I would also work on this for free if you wanted to give me some guidance on how to get other hardware to be compatible with the Espruino IDE.