If you are not afraid of a little work to get to your end result you can get an even bigger build volume. This printer has a build volume of 600mm x 600mm x 600mm..

Tronxy X5SA-600 Large Direct Drive 3D Printer 600*600*600mm – Tronxy 3D Printers Official Store

You can buy that build it and then you can buy the dual filament upgrade kit for the 500 pro here..

Tronxy PRO-2E Upgrade Kits for X5SA-500 PRO to X5SA-500 PRO-2E – Tronxy 3D Printers Official Store

Apply that and then you just have to correct the X and Y dimensions in the printer firmware from 500x500 to 600x600 for X&Y. This path will let you build up to a 2ft cube