yeah, the physical shutters in the CSU-X1 is more of a “safety” shutter. We typically have it open when the software launches, and close on shutdown (definitely not as an active shutter during the experiment … the is more than sufficient for that)
that said: you don’t technically “need” it at all! If you’re not still under warranty, you can simply remove it from the light path. this requires remove the screws holding in the laser fiber launch, where the fiber enters the CSU unit, then remove the tiny little chip and shutter and put the fiber launch back on… do be careful not to adjust the alignment/tuning screws, just the mounting screws. (I don’t have a photo of that to end at the moment)