As for embeded fx.
I try to make a mixer layout in my custom theme.
1. When you deal with extended area of fxlist etc. you see for example using mcp_fxlist_norm that full width image filled by coloured rectangle not fit. Two pixels on left lack. Bacuse of that to achieve symetrical track graphic you can add 2 "yellow line" pixels or turn off 2 pixels on the left and that is what I did. When you do so all is great but... These new FX view can not be fixed and
2. When displaying ebeded fx, empty cells graphics are shifted.
Mayby these are "nitpicky" things and 2nd thing could be like this by design but these makes things look weird and another pain for themers
Screens are from my custom theme but in default 5 and 6 is pretty same.