Cat Cams confirm CSL is 268/264. I have also seen these same durations from a well respected tuner, so I'm pretty sure they're right.
https://www.zpost.com/forums/showthread.php?t=1596385
"Additionally, I'd like to also offer the OE CSL Camshafts for those that want to keep things factory BMW and for cool factor, as well as OE CSL Exhaust Valves, and OE BMW (Non-Coated) Followers. For those with CSL airboxes, the CSL Cams should keep things simpler as you could run the base CSL tune file without worrying about adjusting for cam values. Please note that these cams do not count toward the 21+ orders needed for the Cat-Cams Group-Buy. There is no minimum order for these OE BMW CSL parts.
OE BMW CSL Camshafts (268/264): Pricing to come shortly
*for reference, the stock M3 camshafts are 260/260."