That is what they say at https://shapeshift.io/about.html
"You can reuse deposit addresses. If you do, the converted amount will be sent to the same output address as before."
Thereās one important remark:
itās only true as long as you donāt use the āspecific amountā function. The addresses generated for specific amount orders canāt be reused.
Hi, there! We have a few things that we look at when deciding to add a new coin. The main factor is having enough people reach out and tell us they want it. Via our social media channels, chat, email, we listen to what people they they want. We will take this request into consideration!