QML Id length is limited to 20 characters

Qt Sketch Bridge limits the Qml Id field to 20 chars.
When using longer names in Sketch those might get overwritten if the name differs only after that 20 char limitation.

Qml-id was used as an asset file name till QDS 1.4 so we limited the size of the file name to mitigate the windows file path limit. Since asset names use UUID now, the limit is irrelevant.