A new useful GIMP feature is available in git version.
Much needed addition to already existing pixel and alpha channel lock for layers, pixel lock for RGBA channels and path stroke locking features.
Hope it comes as bug-less as possible......well, considering the complexity of the feature there are certain concerns it could be buggy at first.
Good news!

I fail to see the purpose of some this... Alpha lock is OK since paint ops apply RGBA and sometime we want to keep the A. Having explicit locks on other channels could be useful in some cases (but not restricted to the brushes).

But when is a layer/path moved/scaled/rotate when we don't explicitly want it to happen already?

Haven't tried transformations lock yet (can't do much production-wise in git version) but if it is going to work as intended in stable version, I can see the benefits of having new feature right away.
Sometimes need to scale down 30-layer image but keep some layers/layer_groups and paths intact (e.g. svg file imported from Inkscape can contain few layers and dozens of paths I don't want to change). Text layers if I wanted to adjust image size but keep text size precise?
There is a dozen of scripts I can think of immediately (and it's just me) when I need layers/paths locked: all scripts and plugins that transform the whole image instead of intended layer(s), some other scripts recently used by me - animstack, move/rotate/scale by path (it not only moves layer but also moves and transforms the path), align layers - I wish I had that feature. Etc, etc, etc.
Haven't thought of channel transition lock usefulness, but can't exclude some users will find it useful too (gotta ask RemyDev who wrote the patch or mitch who improved it).