<transform from="x[\u{1234}]y"/> does not work - the char class [] only accepts ranges, not single chars. [\u{1000}-\u{1020}] is ok.
<transform from="x[\u{1234}]y"/>
[]
[\u{1000}-\u{1020}]
🎉 Looks good!
Accepting this as a followon to CLDR-16836
<transform from="x[\u{1234}]y"/>does not work - the char class[]only accepts ranges, not single chars.[\u{1000}-\u{1020}]is ok.