Kind of a "useless" overflow if it doesn't have a "hole" in it...don't you think...
Actually though, "if" he is not including them and will be charging "extra" let me know... because I have an "alternative" plan for the oveflows and return line...
Here additional hole "E." is 1 1/2"... located in top of Euro Bracing,2 1/2" left of center, no bulkhead, for OTT return pipe...
Now you only need 1 hole each overflow, 1 3/4" for 1" stand pipe (location "D.")
So now your total is...
(1) 2 3/8" hole with 1 1/2' bulkhead...(A.)
(4) 1 3/4" holes with (4) 1" bulkheads (B. and D.)
(3) 1 1/2" holes , No bulkheads ......(C. and E.)
Got it...??