Windows are nice. I don't however know the motivation. 'Frameless' seems a visual-but I haven't pursued the advantages. Dual pane anything is desirable.
Rear umbilical, I'd agree with others, I'm not sure. I know many folks do utilize the bumper plug for camper, for whatever reason don't add a dedicated bed plug. In that case it would save some wire lengths and the minimal cost to add bed plug. I simply see it, unless batteries (&weight)are toward rear just more unneeded wire.
For those that tow would still require adding another plug or y adapter. Or worse running an extension to use existing bed plug.
Id be rewiring the camper for front plug. For me getting under camper to plug in, the extra wire run, rear umbilical doesn't sound like an 'enhancement'.