GeoJSON text sequences have no security considerations beyond those of JSON text sequences and the GeoJSON format.
The advantage of using ASCII character RS "0x1e" to denote a text is that sequence producers and parsers need not enforce a canonical form of GeoJSON. Any valid GeoJSON, pretty-printed or compact, can be used in a GeoJSON text sequence.
A variety of parsers designed for newline-delimited sequences of compact JSON text are deployed on the internet today. While there is no canonical form for JSON texts, and pretty-printed and compact forms are equally valid, GeoJSON text sequences containing compact GeoJSON texts with no internal newlines are more interoperable with existing non-standardized parsers.
In a distributed system where order and exactly-once delivery of messages are difficult to achieve, GeoJSON text sequences that do not rely on order of texts for extra semantics are more interoperable than those that do.