Implementation Option Matrix

Purpose

This matrix keeps future cuts from turning into flavor arguments. Each row names the invariant a subsystem must protect, the conservative implementation, the aggressive implementation, and the proof that should decide between them.

Audio Sync Receiver

Option	Protects	Upside	Failure Mode	Proof
Current window decoder	Correctness oracle	Easy to inspect; already wired	Repeated full-window work	Keep as reference until streaming matches
Streaming scalar decoder	One-pass receiver state	Small, portable, phone-shaped	Weak proposals can miss path-damaged chirps	Synthetic/artifact parity with fewer scans
AVX2 scorer	CPU throughput	Fast fixed-bin scoring	Interop and memory traffic erase wins	Batched benchmark beats scalar end-to-end
GPU scorer	Large batch throughput	Many channels/candidates at once	Dispatch/readback overhead	Only promote when batches are large and GPU stays resident
Full chirplet transform	General signal analysis	Handles unknown chirps	Too broad for controlled codebook	Only if controlled receiver fails after calibration

Active Witness Shape

Option	Protects	Upside	Failure Mode	Proof
32 fixed bins	Short triplets	Dense code space	Dead/aliased bands in room	Works only where response is good
Adaptive reliable bins + higher order	Physical robustness	Avoids dead bands	Longer lock window	Meatspace anchors increase after calibration
Watermarked hybrid	Human tolerance	Less annoying	Masked too well to decode	Passive+active confidence improves without audible abuse
Ultrasonic-only	Low distraction	Clean separation from music	Monitors/mics may not pass band	Measured SNR and response beyond hearing

Audio Actuator

Option	Protects	Upside	Failure Mode	Proof
Integer delay	Coarse alignment	Simple	Not microsecond/subsample	Useful only as baseline
Farrow fractional delay	Subsample delay	Cheap, time-varying	Magnitude/phase ripple	Delay residual falls on artifact and live captures
Variable ASRC	Long-term SRO	Holds sync over time	More complex buffering	Drift stays bounded over 20+ minutes
Frequency-domain phase correction	STFT coherence	Good for analysis frames	Latency/window artifacts	Program material remains clean

Audio Field Reconstruction

Option	Protects	Upside	Failure Mode	Proof
Aligned stems	OBS usefulness	Immediate production value	Not volumetric	Stems stay synchronized and mixable
Source-based spatial bus	Coherent performance mix	Honest with sparse mics	Depends on source metadata	Stable source positions/pans
Ambisonic fit	Compact spatial field	Standard ecosystem	Sparse irregular mics unstable	Calibration proves usable order/band
Sparse equivalent sources	Physical field estimate	Handles arbitrary geometry	Ill-conditioned inverse problem	Known source reconstructed with residuals
Hybrid evidence field	General Mimir shape	Combines audio/visual constraints	Complexity creep	Fensalir reservoir stabilizes claims

Camera Ingest

Option	Protects	Upside	Failure Mode	Proof
JSON probes	Research observability	Fast to inspect	Not a hot path	Keep diagnostic only
Managed wrapper over native reads	App integration	Easier first driver	Copies/GC pressure	One camera sustained cadence
Native SPSC frame rings	Throughput	Predictable hot loop	ABI/lifetime complexity	All local cameras sustained
GPU shared textures	Copy avoidance	Best final path	Driver/API friction	Fensalir imports and renders frames

Visual Fusion

Option	Protects	Upside	Failure Mode	Proof
Feature tracks	Sparse evidence	Debuggable	Not visually rich	Tracks align across cameras
Point/splat claims	Live volumetric surface	GPU-friendly	Needs calibration	Stable live render from observations
Offline 3DGS-style optimization	Visual quality	Mature papers/code	Wrong latency/ownership	Use only for reference or static assets
Dynamic/4D splats	Live field	Target shape	Research complexity	Start after direct observations work

Fensalir Boundary

Option	Protects	Upside	Failure Mode	Proof
Mimir builds render state	Quick local control	Tempting	Duplicates engine	Reject
Mimir lowers contract frames	Ownership clarity	Clean boundary	Needs stable contract mapping	Allocation-free lowering benchmark
Fensalir owns temporal evidence	Single field authority	Reuses engine work	Requires good candidates	Acoustic/visual claims visible in engine