Andrea, thank you for locating these improvements. My commentary below is not meant to be too picky, just suggestions that you can ignore. If you agree with my suggestions, no need to resend Plugins.tex because I will just make the changes accordingly. These are the result of my doing "Check that they fit", but I have not reviewed it all yet.
1) "The following effects support OpenGL acceleration:" - I am not sure that it is important to list these as either the person wants to use the plugin or they do not so they probably do not care if it uses OpenGL. I would leave this out unless you think it is really important. And the list is missing several per the search I did which may not be 100% correct to include:
colorspace/colorspace.C:#ifdef HAVE_GL
downsample/downsample.C:#ifdef HAVE_GL
flash/flash.C:#ifdef HAVE_GL
lens/lens.C:#ifdef HAVE_GL
mirror/mirror.C:#ifdef HAVE_GL
motion51/motion51.C:#ifdef HAVE_GL
rumbler/rumbler.C:#ifdef HAVE_GL
scaleratio/scaleratio.C:#ifdef HAVE_GL
swapchannels/swapchannels.C:#ifdef HAVE_GL
zoomblur/zoomblur.C:#ifdef HAVE_GL
zoom/zoom.C:#ifdef HAVE_GL
2) The added line "The contents of the Mask track can be processed further (blur, color correction, further masking) after the plugin." would go better on the end after "animated Mask in one track and then to transfer the Alpha channel to another target track" because that is where Mask is being talked about.
3) Since ChromaKey implementation has varied so much and CinGG's version has a problem, I am not sure if this is correct in our case: "It uses the same algorithm as the Gimp selection tools. It works best with computer generated graphics." Anyway to test this and verify in a case where it does work?