The reason for the disconnect being added is due to the second transformer being needed after it was discovered that the POCO transformer was 480v, not 240v as called out in the drawings.

I agree the best remedy is to relocate the 3" raceway that feeds the 480v-240/120v tranformer from the meter pedestal to the disconnect. I am guessing this would require substantial work.

I believe the POCO transformer is 3phase 480volt.

Now, if the disconnect was equipped with locking tabs that the POCO could install their own lock on, would that satisfy the worry of having someone tamper with the feed before it hits the meter ?

The G.C. probably told the E.C. to correct the problem the cheapest way possible because he (G.C.) doesn't want to go back to the cell company with a change order for the additional work. The E.C. should have insisted the 3" raceway be relocated to the disconnect.