Should I turn the Reference Gamut Compression (RGC) on or off when using ACES 2.0 in Resolve, and what do ACEScentral practitioners say?

Forum record (2025): an April post expected RGC to be disabled by default in ACES 2; a June post said RGC was not for ACES 2; a reply speaking for the group ('We think') corrected that there is no recommendation for or against RGC in ACES 2, which stays compatible but is expected to be unnecessary in most cases; a December LMT author still applied RGC after the LMT as a stopgap. Answer: optional, not prohibited; no specification text read. Curator qualifications: Documents/posts read 2026-10-22; no EDL, ALE or AAF exported or conformed. Forum posts, not ACES specification or Resolve documentation; poster affiliation inferred from wording only; poster names not recorded. Resolve default (RGC on) is one user's installation. Curator amendment CA-AM-0083 (2026-10-22): Primary ACES documentation (aces-aswf/aces-docs main 7c34c210, read 2026-10-22), scoped negative plus context. (1) The RGC user guide (docs/rgc/guides/rgc-user/index.md, readback a46b51530a3a836a) recommends, 'in the current absence of AMF for tracking', that most productions use gamut compression everywhere. It says the RGC is 'always on' by default in any viewing pipeline and baked in at the appropriate stage. The page never mentions ACES 2 or a 2.0 Output Transform (curator search: 0 hits for 'ACES 2'). (2) The rendering background page (docs/background/about-rendering.md, readback c6dc9bfc8ec227c1) captions a comparison 'ACES v2 (left) vs RGC + ACES 1 (right)'. It says ACES 2 'does not exhibit the same clipping artifacts' and that the RGC 'was developed specifically to minimize clipping artifacts with ACES 1'. (3) The RGC overview (readback 22e399e07d17d08e) gives no ACES 2 guidance. The docs therefore imply the RGC targeted ACES 1 artefacts, but give no statement on whether to keep, drop or change RGC use with ACES 2 (inference, not a source statement). The always-on recommendation is written in ACES 1-era terms. The open question stands. Resolve's default RGC behaviour was not checked: the Resolve manual was not read. Curator amendment CA-AM-0084 (2026-10-22): aces-core CHANGELOG.md at main 069b0bc3 (readback 67bdb6545b3f5804) records the RGC as a v1.3 addition (April 30, 2021: 'Add gamut compression transform to assist with remapping problematic colorimetry into AP1'). Its 2.0 entries (April 4, 2025 and the developer releases) mention only the Output Transform's internal 'gamut compress functions'. These belong to the 2.0 rendering, not the RGC LMT. No entry deprecates, removes or re-recommends the RGC for 2.0. Same scoped negative as CA-AM-0083. Do not conflate the ACES 2 Output Transform's internal gamut compression with the RGC LMT. Limitations: Documents/posts read 2026-10-22; no EDL, ALE or AAF exported or conformed. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://community.acescentral.com/t/5812.json",
      "note": "ACEScentral topic 5812 post 8 (2025-06-24, post JSON); ACEScentral topic 5812 post 10 (2025-06-25); ACEScentral topic 5770 post 12 (2025-04-20); ACEScentral topic 5812 post 48 (2025-12-09)"
    },
    {
      "url": "https://community.acescentral.com/t/5770.json",
      "note": "ACEScentral topic 5812 post 8 (2025-06-24, post JSON); ACEScentral topic 5812 post 10 (2025-06-25); ACEScentral topic 5770 post 12 (2025-04-20); ACEScentral topic 5812 post 48 (2025-12-09)"
    }
  ]
}