As said it repairs everything at the same time at 3hp/s. Maybe it should just have a total repair rate, and that is divided by all buildings that need repairing in dc range? And at niveus default you can build a base with 5 reps, 3 nodes, 2 armos, 2 medis, 11 rets, dc (2 bps left over), or replace 1 node with 2nd dc (4 bps left over). So that base sure has room for it.