Chastity cage? I didn't get this scene, only a edging scene.Yeah, I'm not a fan of that either. Though Emma had a lot of content in the 1st chapter and she was absent in the 2nd, so I assume that now - especially that I haven't even started any route with her - Jen will be just there. Dev promised to make chapters with changing focus between the girls and I hope we'll get to see some good Bri-focused chapter soon.
With Lea I think (I'm neither on her's nor Jen's route) you have to do all her exhibitionist content, choose sensitive options whenever you can, start a Deb route and accept chastity cage and when MC will have a chance to do smth more with Lea explain to her why he is in a cage. With Jen I'm not sure, I think it's a mix of decisions (you definitely can't stay professional with her) and sensitive dialogue choices.
BTW there's a new gameplay update with new hint menu about what skills girls will need in the future (based on info found in the dialogues), lovemeter menu was reworked, some mechanics were removed and chapter 3 got extensive proofreading.
Jen you need to go down on her and choose all the sensitive options