"Image > Precision" renamed to "Image > Encoding" in 2.99
Per gimp@7025039b and gimp@eec1df23
I fail to understand the implications of the latter when it comes to the mentions of Perceptual gamma
on https://testing.docs.gimp.org/2.99/en/gimp-image-precision.html
Furthermore, https://testing.docs.gimp.org/2.99/en/glossary.html#glossary-channel-encoding mentions In GIMP 2.10 two different channel encodings are used internally for various editing operations, these being "Linear light" and "Perceptually uniform (sRGB)".