computational geometry - Can't plot rotated region

I was experimenting with the code from this question when I ran into another problem with regions.

Ω = RegionDifference[Rectangle[{0, 0}, {10, 10}], Rectangle[{4, 4}, {8, 8}]];
RegionPlot[Ω]

Ω1 = TransformedRegion[Ω, RotationTransform[45 °, {5, 5}]];
RegionQ[Ω1]

True

RegionPlot[Ω1]

RegionPlot::invplotreg: TransformedRegion[RegionDifference[Rectangle[{0, 0}, {10, 10}], Rectangle[{4, 4}, {8, 8}]], TransformationFunction[...]] is not a valid region to plot. >>

What is the difference between a "valid region to plot" and a region that satisfies RegionQ? Or, perhaps, to put it better, am I seeing a bug in RegionPlot or just an incomplete implementation?

I note that

RegionPlot[TransformedRegion[Rectangle[], RotationTransform[45 °, {.5, .5}]], 
  PlotRange -> All]

works as expected, so it would seem RegionPlot can handle rotations for some class of inputs.

Answer

Here is a workaround:

r1 = RegionDifference[Rectangle[{0, 0}, {10, 10}], 
   Rectangle[{4, 4}, {8, 8}]];
r2 = TransformedRegion[r1, RotationTransform[45 \[Degree], {5, 5}]];

mr = DiscretizeRegion[r2]

And then:

RegionPlot[mr]