UsbSerial supports the problematic CH340/341 chipset from 3.0 but the implementation lacked of some necessary features. Finally I managed to get some time to improve CH340 and I gladly announce that CH340/341 support has taken a very long leap!
– Broader range of baud rates supported: 300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600
– Flow control support for RTS/CTS and DTR/DSR.
– All parity modes.
With this new driver the support for the Arduino clones should be better.