There is some cross compatibility between the XR Classic/Recurve and the Onewheel GT Accessories.
The XR Classic/Recurve has the same charging port as the GT and ships with the GT Home Charger. This also means that the GT Hypercharger is also compatible with the XR Classic/Recurve. The charger plug for the GT is also compatible with the XR Classic/Recurve and if you bought a bundle, your charger plug may also have the GT Branding. Please note that the XR Classic/Recurve is NOT compatible with the GT S Series chargers.
In addition, the XR Classic/Recurve also has the same rail dimensions for the front and rear footpads as the GT. This means if you already have Footpads for your GT or GT S Series board, they will work on the XR Classic/Recurve boards.