A friend of mine gave me a duet WiFi board...

A friend of mine gave me a duet WiFi board… And I have a prusa i3 type of printer…

Shall i build other printer based on this new board (corexy) or just install it on my actual printer?

Install it on exist printer for now and learn as much as you can from it while you sourcing parts for new printer.

If you want to explore the full potential of Duet wifi, build a new corexy with dual extruder…