If you use 512x512px tiles instead of 256x256px tiles, make sure you display them correctly in your map viewer. Users sometimes use the 512px tiles without properly adjusting the viewer on their website/in their application. The incorrect usage is recognizable by checking the size of the labels on the displayed map. Tiny, almost unreadable labels show that the 512px tiles are used incorrectly.
The incorrect usage of 512px tiles generates up to 4x more requests compared to the correct usage. It is recommended to either switch to 256x256px tiles, or keep using the 512x512px tiles but modify the map viewer so that it recognizes that the downloaded images are in the 512x512px resolution. See an example and focus mainly on the tileSize and zoomOffset parameters.