We also have an Outback trailer, like yours. Ours doesn't have the bathroom so came with bunkbeds. Friends who had your model found that the making up of the bed each night became a real chore when the other person had to sit on the toilet, out of the way, while the "magic" of the transition was taking place.
By having your beds where you have configured them, am I correct in assuming that you still use the dinette to eat from and also make up your bed at night? Are you tasked with storing the wooden bed parts for the kids' beds in your tow vehicle (as I know there'd be no place inside the trailer to store them unless they come apart small enough to place on the dinette seats/under the cushions). Will you have some sort of guard rail to protect them from falling?
Actually, the bed at your feet very closely resembles a shelf we made to accomodate our electronics--laptop, bluetooth speakers etc. We use it for watching "tv" at night from the computer.
You have come up with what looks to be a viable solution while still keeping yourself access to the bathroom area. Modifications are ALL about doing something different that works FOR YOU. Good job!!