changesOutsideCapture property
How many frames the watch saw a change that missed every slot of the atlas.
A counter rather than a flag because "a shared texture is a shared dirty flag" is an argument about a rate: a mechanism that pays on 3% of frames and one that pays on 90% call for different designs. It is separately readable from generation on purpose — a report that only counted publishes could not tell a screen where nothing moved from one where everything moved away from the glass.
Implementation
int changesOutsideCapture = 0;