Call me crazy, but I still don't see how you can get a drip tray to work. For a drip tray / trickle filter to work well, the media needs to be higher than the next baffle in the line.
Side note: the water level in the sump will equilibrate with the return section of the sump, or in your case the return section and poret foam section since there isn't an "over" baffle to the left of the last baffle, essentially making the last two baffles one section with something at the top.
Anyways, if you place the drip tray in line with the first baffle (just under where it reads "poret foam, wet/dry drip tray"), the bio bale will be underwater.
Does that make sense? It's kinda hard to explain in writing, but essentially the water will have to rise to the level of the baffle between the bio media and the last poret foam section (just left of center in the pic), meaning that the water will be just as high in the drip tray section : the water doesn't magically all go to the left of that baffle after the drip tray and then build up and spill over the next baffle without an equal amount of water on the other side.
Side note #2: If you want water to flow properly and not end up with a dead spot on the surface of the water where everything is, make sure the baffles decrease in height going towards the return. That way there is always a net downwards flow of water. In my sump (20L), there is about a 1/2 drop in water level as it travels to the next section. **You may have already planned for that in your drawing, but I can't tell what the measurements are. Either way, I figured I would throw that out there.
^What I would recommend is add a baffle to the left of the very last one (the one that is suspended above the bottom of the tank just before the return section) and make the height slightly smaller than the baffle between the poret foam and bio media. That way you'll only net water loss in the return section rather than the return AND final foam section.
Either way, I think it looks better without the fuge and having a larger return section means you'll probably have less frequent top offs (depending on other factors.... have you thought of getting an ATO?). I'll draw up a quick picture (I'm a bad artist so don't laugh at it haha) for what I'm talking about.