A dishwashing appliance or removable rack accessory may include a rigid upper strut, a rigid lower strut, and a plurality of intermediate struts. The rigid lower strut may be spaced apart from the rigid upper strut along a vertical direction. The plurality of intermediate struts may extend between the rigid upper and lower struts. The intermediate struts may be generally movable along a transverse direction relative to the rigid upper and lower struts. The plurality of intermediate struts and the rigid upper and lower struts may collectively define a plurality of variable apertures extending through the removable rack accessory along a lateral direction to receive one or more container lids therein.