I used a large building of separate rooms, then connected them all by making a line in the floor across the building (perpendicular to the barrel rows on first and second floors) and put 1 cobble in each of those to be hidden/ignored.
I use ender chest > filter > pipe > router
ender for obvious reasons > filter to pull by the stack (reduces performance issues over spamming transposers) > a pipe to keep the filter and ender chest from being accessible to the router > router with a transposer on the side to a differently colored ender chest that I'll pair in the front of the building so I know what needs sorted.
(Redstone pipe happened to be the first one I found, not needed.)
I thought about using 5 transposers, but I don't plan to ever set up a mass quarry so this should be fine. I might replace it with a biogas engine and a wood pipe since I produce a ton of oil.
This works well enough for 4 turtles excavating at the same time into one chest, mostly cuz turtle will keep trying to dump until they can.
If you turn the timer below 0.8 sec you'll need to delay the transposer. This could be solved with an item detector and a toggle latch, but I won't need it that fast.