The BMR lower control arms were designed shorter than stock to offset some of the negative camber that you get when you lower the rear. Many guys with lowered cars could not pull the bottom in far enough with the stock adjusters to get back to reasonable rear camber numbers. They were way to negative for street use. The shorter BMR arms naturally pulled the bottom in and allowed factory or near-factory settings. However, if you were not lowered enough, you had the opposite problem. The stock or even extended range adjuster bolts could not push the lower arm outward enough to get much negative camber. The amount this affected each car varied with how much or how little it was lowered. The more you are lowered the better the BMR non-adjustable arms will work for you.
I do not know if BMR has changed the LCA as it was quite a while ago I had the issue of not being lowered enough. The BMR LCA were a great idea to let guys who are lowered obtain good alignment numbers without needing special adjusters, etc. My ONLY problem was I was not, at the time, lowered enough.
I ended up replacing the non-adjustable BMR rear LCA with their adjustable version. They are fantastic and any alignment is fast and easy and they have a very large adjustment range.
The rear toe adjustment and rear camber adjustment interact a LOT. You must work both toward your target camber and toe values interactively.
Loosening the upper control arm's inner mounting bolt and pushing the arm inward will have the effect of shortening that arm and it can offset some of the effect of the short BMR rear LCA. Make sure to get those bolts tight. An added benefit is that pushing both rear upper control arms inward with reduce bump-steer.