The 4 1/2" conduit seems a little strange.
As earlydean has said in our area the metering CTs would be inside, I tried to get the local POCO go with this setup before due to space limitations in the building, they said they do not want metering at the transformer in case a replacement is needed they won't have to get the metering guys involved with the swap out.
ayrton and Megawatt, this appears to me to be a 1,200 amp service, 3 sets of 600s, assuming copper.
Are you saying you would rather run 5 sets of 250s in place of 3 sets of 600s?
Why?, more time more material.
I would not try or want to use smaller cable 600 kcmil is great in 3 1/2" conduit.
My wild guess is that Note 4 should read.
"4) PROVIDE 3 SETS 4 #600KCMIL-3 1/2" C"