appInfoLimits top-level constant
App Store Connect's limits on the listing text, in UTF-16 code units.
Over-counts anything outside the BMP, which is wrong in the safe direction: it rejects here, where the fix is free, rather than at Apple after the screenshots have already gone up. Emoji are the case that makes this non-theoretical, and CHANGELOG.md is full of them.
Implementation
const appInfoLimits = <String, int>{'name': 30, 'subtitle': 30};