Underground runs of aluminum, size increased for VD, land in electrical room at an entrance point, then transition to copper in EMT which goes to various pieces of gear. Would the CU segment need to be upsized as well? For example 20ft of CU in EMT which hits a junction box, then 250ft of AL to the load. The 250ft of AL would be increased size for VD. Does the run of CU have to be upsized as well? Also wondering the best way to make that transition. Is there a terminal block with threaded studs where compression connectors can be used on the wire?