I found out that you can rename most VST-DLLs and since renoise does sort them in alphabetical manner …
now I gave my Plugs little decriptive prefixes in the filename, like
f_chorus.dll (for flanger effects)
v_maximizer.dll (for volume effects) or
e_grungelizer.dll (for effect-effects 
)
helps you to scroll through the list.
does not work with all plugs though.