Best USB-DMX dongle

[Arti G]

Currently I use cheap 3$ usb-rs485 from Aliexpress with no isolation. They are working properly for at least year. 
Do you think it's neccesary to have isolated DMX outputs? As far I know Enttec OpenDMX doesn't have isolation. 
But I think if I should start using something better. What do you think about this DIY design? Is it best design for usb-dmx? Maybe some tweaks are needed?

So far I have seen adapters with 2 TVS diodes on outputs, or one SM712. Some had 10R resistors from A and B IC3 outputs to DMX connector, or 100R between DMX pin 1 and ground. Maybe such protection isn't needed with ADM2483BRWZ? Or it would be better to add?