There is no esm file, just a bunch of esp files, and the BSA packaging shouldn't be a problem either, it is just a way to keep the various other files (textures, meshes, sound...) together a bit better, not really any different than having a bunch of folders to install in the Data folder.
I am using Wrye Bash for this mod nowadays (which means one has to modify the ini file manually, but other than that is cleaner) but did the OBMM script run through properly?
Have you activated the added esp files - especially bgMagicEV.esp?
Is that file (at least) and the bgMagicEV.bsa file both in your data folder?
It sounds like you failed to install it properly in some way, if the esp files aren't in your load order. Because the latest version of the mod does work. I
think i used this same version through OBMM and the script/install worked fine.