Hey Don, good job! The return lines are very nice. Thanks for the pics. I was also concerned about having to cut the trim. Again I used 2 paint sticks stacked as a shim. Steve is correct a paint stick is what You get when buying a gallon of paint. I could have used 1 stick. I think if I hadn't used any sticks as shims, I would have had to cut the trim. Any way with 2 sticks the water level is "just" above the trim and not seen. Hope that makes sense. Don, I think You will be fine with the water level. It shouldn't be visible.
As for the height of the stand pipes, (Just my opinion here) 1st don't glue the stand pipes inside the box . The 3 bulkheads ,left to right. 1st was the emergency tallest. I set it at 5 1/4 inches 2nd pipe (center )was the siphon. this was the short one . . I had to take off about an inch. ended up with 2 1/2 inches the 3rd far right was the trickle. Set at 4 1/2 inches. Once you water test You will easy tell if the heights are ok. Personally I won't glue the stand pipes or will I use inverted 90's I will figure out a type of screen. It was lot less complicated than I thought. Now getting the ends of the drains at proper level into the sump took some work also. with the drains right at an inch or so below the water surface in the sump, I can turn off the pump, restart and it immediately goes right back to siphon. I can close the siphon valve and the trickle and emergency drains easily handle the flow. Very nice design.
This over flow is so quiet it's kinda freaking me out. I keep thinking it's not running any water thru it! Just tonight I filled the tank with sand and water every thing is running as advertised . And that's a 1st for me!