IT LIVES (works)!
Details: Current Nvidia Shield Experience 9, PMS 1.27 running on the Shield, tested with iPadOS and web clients with explicitly-set quality settings to force transcoding. Transcoder settings: Disabled HDR tone mapping (per linked comment), checked “Use hardware acceleration when available” and “Use hardware-accelerated video encoding”. These are the same settings/circumstances that would previously fail to transcode and throw the errors in the Plex console.
Thank you, @anon18523487!
