I did the OCC install. The stock hoses are a pain in the ass. The clips do not want to unhook and they can break easily. Like you, the hoses had to be muscled on. My hoses were actually a bit too short, so I went to an automotive shop and got new one.
after 3k miles my OCC had zero oil in it.
MY Build Log
08 AW 135i | Cobb | ETS FMIC | ER CP w/ Tial Bov | AR Catted Downpipes | Berk Mids | Meisterschaft GT SUS 1M |M3 Control Arms | M3 Sways | M3 Rear Subframe Bushings | Wavetrac LSD | AST 4200 DA Coilovers | HRE R43 | Hankook R-S3 |Full BMW Performance Interior | Revozport 1M Raze Aero Package in Satin Carbon |1M Body Conversion|