Hi, I'm also married to a serial cheater and here's one thing that the discovery of this has really hammered home for me: the multiple infidelities aren't something your husband did, they are an expression of who he is. Who he is, how he feels inside, how he feels about marriage in general.
He doesn't have boundaries around your relationship, so his behavior reflects that.
He is currently trying to create artificial barriers to cheating, like the Life360 and passwords, but first of all that places the burden on YOU to track him and trace him and hold him accountable. That sounds like a full time job for you. But none of those artificial barriers change that he himself doesn't respect your marriage. If he truly respected it, his behavior would reflect that and it simply does not and very likely will not.
Essentially he's like a dry drunk right now. All of his feelings, thoughts, coping mechanisms and preferred behaviors he had while cheating are still all there inside of him, he's just (maybe) currently holding himself back from cheating under duress. But that temporary duress doesn't change all of the parts of who he is inside that made him want go to marital therapy with you for infidelity while simultaneously having sex with other women and telling them he wants to impregnate them. That's who he is, whether he's been threatened into a pause or not. And what happens six months from now when you don't have time to track him or check his phone and that same life stress that makes some months especially busy eats into him and he cheerfully fires up his favorite cheating app? What has fundamentally changed since he was in therapy and also having multiple affairs?
I've really had to come to terms with the fact that my husband is who he is inside, and who he is is someone who doesn't see marriage as a barrier to having relationships with other women. That's a completely consistent through-line in his behavior, as it appears to be for your husband. And yes my husband does feel love for me, but his behavior shows he doesn't respect me, respect our marriage, or even respect himself. Love isn't enough. It needs respect and empathy and the motive to achieve real partnership, which means compatibility in the boundaries around your relationship. So yeah, our husbands probably do love us, but if that love doesn't come with respect and shared beliefs, how much weight does that feeling of love really have in the marriage?
We get to choose whether we want to be in the marriage with the exact person they have shown themselves to be, the person our WH's really are. Not the fantasy of them that we really want to cling to, but do we want to be married to someone who feels the way they feel about marriage as evidenced in their words and actions?
I'm not going to tell you what to do about your marriage, but I do think you should think about yourself right now, center yourself in your thoughts about your marriage during this time. What are your boundaries, your needs, your true feelings about marriage, and are those things compatible with the person your WH is as shown in his most consistent actions? Does he share those boundaries and feelings about marriage? Think about YOU more than you think about him in this process. What do YOU need, and what are YOUR dealbreakers? And can the person you were in therapy with meet those needs and not act on your dealbreakers?