Never mind latin1. What about BINARY, one of the datatypes explicitly supported by dynamic columns?
All other JSON encoders I know error on data that cannot be encoded as JSON. But Maria instead returns non-JSON.
one "problem" about JSON, it only accept Unicode, be carefull when using latin1 + utf8 + json
"2 Conformance
Conforming
JSON text is a sequence of Unicode code points that strictly conforms to the JSON grammar"