Persistent Render Data for Multiple Layers

As stated in the documentary "When using multiple View Layers, only data from a single view layer is preserved to keep memory usage somewhat under control". It would be nice to have the option to disable this behaviour as this massively slows down Render times when having multiple Layers with non-shared objects. Of course this would only be viable on Systems with a lot of RAM/VRAM, thus an optional checkbox. Alternatively the option to render Layers sequentially (ie. first render all frames of the first layer, then all frames of the second etc) would be also a viable option since then the renderdata would only be discarded once it is not needed anymore.

I will attach some snippets of log files to show the difference this can make. In one case i rendered with multiple layers at once and in the second try only one layer. The startup time before each frame after the first one for this layer has decreased by about 44 seconds.