Structured Logging does not log in ISO-8601 Section 5.6 format

I was running structured logs through the Java Driver and I think the timestamp format we’re currently using is incorrect, specifically for timezone offsets, according to the Extended JSON Spec. On 4.3.4 I’m getting timestamps like "2020-03-12T17:38:02.344-0400" which does not include a : in the offset -0400 however the extended JSON spec calls out specifically that it only supports timezones in the ISO-8601 “Internet Date/Time Format” which corresponds to section 5.6 of RFC-3339 where the only valid time-numoffset includes a :.

This ticket should track a solution that allows drivers following the extended JSON spec to parse structured logs as extended JSON objects according to spec. That might take the form of changing the timestamp string's format, adjusting the extended JSON spec, or another solution I can't see.