Can I go to SLC if I'm ARNG and am not eligible for promotion until 2019?

If this gives you any idea: I tried to get SLC (DL) training done and out of the way, but my ATRRS request for that course was denied because I was not on a PPRL. And when I asked my BN CSM (who is a SME on STEP), she stated that because I was not eligible for promotion yet, I would not be able to complete any of the training required. I feel ya, though. I want to get it done asap.

In theory.... I went to SLC as a non promotable SSG, so it's not a wild idea.