Hello! My name is Dr. Bob and I work at Facility 83. I suggest you add a feature allowing multiple SCPs be able to be held in each site, like our SCP Foundations in real life. You should of course add a maximum number of slots to each site though. Maybe another update idea would be adding the ability for SCPs to escape if your Containment Agent number gets too low. Below its capture number maybe. It would add difficulty. Just some thoughts. Have a good day / evening / night!
Edit: Maybe add many more SCPs. The official wiki link is on my profile. :)