Our Open Source project for map rendering is also seeing these warnings. At this time we are not certain if the "Metal Compiler Warning" is causing a performance hit or not. Filed FB9120382 to add our warnings from iOS 14.6 running on a device. See GitHub discussion which has a graph and raw time stamp data, maplibre/maplibre-gl-native #69. This project is migrating from Open GL to Metal. MapLibre GL [Metal Compiler Warning] Warning: Compilation succeeded with: program_source:54:12: warning: unused variable 'flippedFragCoord' float4 flippedFragCoord;

This example may be of use. Both annotation & imgs are arrays. Check that images are served over https. { "annotation": [ {"markerStyle":"img","imgIdx":0,"point":"33.098,-116.66"} ], "imgs": [{"height":25,"width":25,"url":"https://serve/skateboarding.png"} ] }