Well, that makes players hate dying, so that's another reason for them to avoid dying more than ever
Having a whole squad spawning behind the enemy lines is not fun. Also, when halftracks come out, they would a bit useless with the spawn on SL function. Perhaps you could make the halftracks as mobile spawn zones instead of the SL when they come out, like DH did. BF2 kinda did it right because the capzones were scattered across all the maps, so your teammates would also be scattered and catching up with your squad again after spawning on normal spawn zones is not as easy as in RO2.
The current RO2 maps are too small for that function to work right and Butovo isn't much bigger than the others. Look at Grain Elevator, a fantastic map, but spawning on SL and the normal spawns so close to the battle make it a run 'n gun map, with Germans spawning inside the elevator when the Russians are still defending B because the SL went sneaking behind them and started exploiting that function. I honestly think Ogledow and Butovo are better off with it disabled, creating a much slower pace than on the stock maps.