I think I've got the Erdnase grip down pretty well. I've seen a different grip in Card College, which I think if done well is superior to the Erdnase by far. But I cant seem to get the hang of it, it seems impossible to do the buckle as mentioned. Any place I can see it being done to get an idea?
That buckle and subsequent grab can be a neon sign "Knuckle Flash Everyone, LOOK HERE!". Sure it's a standard, sure it can be somewhat mitigated, and certainly some of the best on the planet use it, and opinions are like....well, everyone's got one. . I own all of Jason's offerings and learned a great deal from them all, he's a modern master to be sure.
However, I highly recommend digging into Daniel Madison's work on the bottom deal before you commit to the Erdnase grip, or any other for that matter. Daniels approach to grip, and unifying that grip for every slight (bottoms, seconds, Greeks, centers) including fair dealing, as well as it becoming "your own" grip is absolutely crucial to success IMO. It's a "bigger picture" approach to then learning other classic sleights and not changing grips to accommodate them.
His bottom deal work can be found in The Mechanic DVDs, the ExM project, but I believe the best resource is the most recent Masterclass series. The Bottom Deal Masterclass is extremely useful and all are reasonably priced.
Sure to each his own, but I believe you're doing yourself a disservice to not check it out and avail yourself of some alternatives, especially while you're early in your learning stages.
Good luck to you!