I'm not sure why the instruction wouldn't be applicable for a Cruzbike. I followed the SRAM installation instructions for setting gaps and limits for my mechanical GX and the electronic AXS upgrade. For this component group a gauge is included that makes the gap adjustment easy. As for the gap you have shown, if shifting is sloppy then make an adjustment.the sram instruction say your supposed to have a 7mm gap between the casserole and the idler sprocket. I do not think this applies to our cruzbikes.
The photo shows what SRAM calls a “pad spreader.” They make some different ones that do the same thing. I use these sometimes when transporting the bike with the wheels off.And the pad spacer that came with the brakes looks nothing like the one pictured below