Adobe recently released the Lightroom SDK 11.0. There aren't many changes from the LR SDK 10.0. Adobe long ago stopped putting any significant effort into the SDK, including documenting what's changed. So here are the results of my semi-automated change detection:
Just cosmetic changes.
The Lightroom Classic Programmers Guide
Just cosmetic changes, including a half-hearted attempt at replacing occurrences of "Lightroom" with "Lighroom Classic" (stopping around page 20).
The phrase "uses version 5.1.4 of the Lua language" was removed. This is unfortunate, since LR still uses Lua 5.1.4 and not the latest 5.4.3. (See this bug report.)
New keys added to photo:getDevelopSettings() and LrDevelopController.get/setValue(): AutoToneDigest, AutoToneDigestNoSat, AVcr_stage_local_contrast, CameraProfileDigest, CompatibleVersion, EnableMaskGroupBasedCorrections, MaskGroupBasedCorrections, ToneMapStrength
(ToneMapStrength mayhave been added in 11 -- it's just returned for videos, and it's always 0. Probably a mistake.)
Keys removed from photo:getDevelopSettings() and LrDevelopController.get/setValue(): CircularGradientBasedCorrections, EnableCircularGradientBasedCorrections, EnableGradientBasedCorrections, EnablePaintBasedCorrections, GradientBasedCorrections, PaintBasedCorrections