Welcome back rebooted but I am sorry for the reasons that brought you back
It sounds like you never recovered from the last affair because you never changed the lifestyle that allows him to cheat. You reference him not coming home after work, being away weekends, having devices that you do not have access to, and many other opportunities for him to do whatever he wants with no accountability.
But the main issue here is not just about a lack of EP's, but the fact that your WH is a serial cheater who is actively seeking affairs and probably has been for far longer than you suspect. Recovering from infidelity with such a cheater is far more difficult, because they are ACTIVELY SEEKING affairs. He is looking for ways to get around you to cheat. Which means you would have to create a lifestyle that makes cheating 100% impossible to be safe again. This means he would have to leave his job and be with you 100% of the time, have no access to computers or smart phones, never be allowed out of your sight as he will actively seek an affair. And you would have to keep this diligence up for the rest of your lives. If you do not do this, he WILL cheat again when he has the opportunity to, you know this because you have already been through this.
If he is willing to completely change his lifestyle and make it impossible to have another affair, and you are willing to also change yours to monitor him, there might be a chance. I am guessing he is not, and you don't seem to want to do this either. I know I personally would not want to live like this.