Tileable max-density* belt storage, with I/O.
Up to 4 green in, 3.75 green out. Prioritizes slower belts so max throughput is maintained as long as possible.
Creds to /u/DjinnKahn for the core tiling (~4.76 belts/tile); couldn't find BPs with the border work done so here it is.
I think I found maybe the only tileable wrapping point that allows the row-shifts to be done in-place efficiently.
* There's a marginally more dense one but it sacs throughput.