Yes, you can use 38 spc load data for low(er) power loadings. Compare the powder weights for .357 and 38 spc and they should be the same or slightly lower for the same velocity. Even the low velocity loads will need some crimp for complete ignition. Won't need the heavy .357 crimp, but once set, I leave the crimp setting alone for all loads.
The advantage of using .357 brass for the low power loads is not having to clean chambers. I've seen where a gun shot with lots of 38 spc loads and not cleaned locked up on .357 mag brass. Had to hammer the cases out.
Enjoy