- Http/gRPC endpoints now return an operation struct and accept an optional spanKind param, requiring client code updates; trace and span IDs are now zero‑padded, which may break custom ID‑matching integrations.
- Added multiple new features: collector tags, insecure TLS with CA‑only certs for Elasticsearch, environment‑variable tracer config, tag/log indexing controls and blacklist/whitelist for Cassandra, and custom basepath support in HotROD.
- Included numerous bug fixes, made rollover initialization idempotent, deprecated tchannel reporter flags, and updated UI to version 1.6.0.