Thickening cream in a blender to increase fat content?
The centrifuge doesn't thicken the cream by mechanical action, but by separating the fat and water by their different densities.  The blender allows- not until solid but until ice crystals form,  you to spin, but not to draw off either liquid.  There's a chance that when allowed to settle you'll get layers, but you're more likely to make butter so you'd have to stop just in time, then let it settle.
It might be worth experimenting with freezing the cream and then allowing it to defrost in the fridge without stirring.  This should break the emulsion and cause it to separate, hopefully into layers.