even if you can get the inverter packed into 40in³ or so, the disconnect switch (AC and DC simultaneously) is going to take up *at least* 400in³ if you want to meet most electrical codes and i wouldn't recommend running it without. maybe a custom designed switch could be smaller but *very* expensive. don't even think of plug connectors - you don't disconnect 450VDC under load using a plug unless you really hate your present eyebrow configuration.
then there's the problem of conduit entry/between/exit and connections to the switch and inverter that are going to run into trouble with minimum bending radius problems for the wire itself if you get too tight . . . and you might want to leave enough room in the switch box to get your fingers in there to actually make the hookup.
an off-the-shelf 2kW unit is about 30x12x4in and fully a third of that is the switch so this seems like an exercise in miniaturization to save a little more than half the total volume out here in the real world.