$1 Low-Power RISC-V MCU

The slide says it uses the Bumblebee core, which seems to be an Andes design:

https://www.eetasia.com/news/article/18111601-hope-for-risc-...

It has a nice set of peripherals: USB, CAN, 2x I2S, 12b 3MHz ADC with 2x..256x oversampling (on 16 pins), 12b DAC. It seems the wait for an affordable RISC-V MCU is over.

It is said Rust runs on RISC-V. Is the toolchain really ready for production?