I say don't drop until after the sex scene to see if the outcome is worth continuing or not.
For the chapter, yeah it's too soon for Io to reveal not only that she knows an informant thay may know Iroha's location but he's easily reachable. He's not in a restricted 6 or anything. I feel like it would be better storywise if the group did a mission to gain enough trust to unlock access to the informant.
Also, you would think the dude would ask to have sex with Io himself instead of being into voyeurism. Obviously, if the sex tape of MC and Io gets leaked, it's going to splinter the group since only Shino knows MC had sex with other girls.