The preview changelog 2024-03-08 states "Opus decoder updated to 1.5.1" https://www.foobar2000.org/changelog-win-2.2-preview
Opus 1.5 includes a new decoding feature (LACE/NoLACE) which is a postprocessing filter: https://opus-codec.org/demo/opus-1.5
However, the complexity on DECODING neets to be set to enable these - see https://hydrogenaud.io/index.php?topic=125597.msg1041651#msg1041651
There now is a opusdec exe with the complexity set - see https://hydrogenaud.io/index.php/topic,125597.msg1041927.html#msg1041927
=> Does the libopus library in Foobar 2000 have this set to enable LACE/NoLACE decoding, and would you add an advanced option to set the decoder complexity (6 for LACE, 7+ for NoLACE)? Edit 1: This affects decoding the new DRED feature, too.
Edit 2: This is how qaac does it: https://github.com/nu774/qaac/commit/4770366db1ad632a2d21fdb5992331d8c8733e84