Flight-test request: D-term pre-diff LPF behavior on noisy frames

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I am looking for flight-test feedback on the D-term pre-differentiation LPF work before it can be useful upstream.

Useful feedback:

• Blackbox logs on noisy frames with dterm_lpf2_hz disabled and enabled
• motor temperature notes after short hover and active flight
• D-term noise comparison around 200Hz, 250Hz, and disabled
• any unexpected behavior when changing PID/filter profiles

Related upstream PRs:

• flight/pid: add D-term pre-differentiation LPF (dterm_lpf2_hz) iNavFlight/inav#11464
• flight/pid,sensors/gyro: D-term pre-diff LPF + code quality improvements iNavFlight/inav#11465

[19379353560]

Update: I published a central contribution hub with good-first issues, review requests, and the D-term pre-diff LPF flight-test guide: https://19379353560.github.io/contribute.html

For the INAV D-term LPF work, the most useful next feedback is same-frame Blackbox comparisons with dterm_lpf2_hz disabled, 200Hz, and 250Hz, especially on noisy frames.

[19379353560]

Update: I published a focused technical note for the D-term pre-diff LPF work:

https://19379353560.github.io/dterm-prefilter-technical-note.html

It explains why the LPF is applied before differentiation, why dterm_lpf2_hz defaults to 0, and what Blackbox comparisons are useful for PR #11464. The most helpful test data is still same-frame logs with dterm_lpf2_hz disabled, 200Hz, and 250Hz.