I would switch cold turkey. We never used pads at all. I took Loki out to the yard from the day we got him, we just kept him on a short leash near the door. Both of mine are house trained, Sammy was 10 months when we got her and she had a lot of accidents but she picked it up in a few months. They ring a bell when they want to go out. They go out a lot and I do have to accommodate their schedules, but I prefer it to them going in the house. Loki has a medical issue and he goes out to pee constantly, but he also pees a gallon every time he goes so pads would never work anyway. Sammy goes out when Loki goes out, but she doesn't actually have to go that often. Maybe every 4 hours if I wasn't letting Loki out anyway.
The expen is fine if it's on tile or you can use a crate too to keep him in when you can't watch him, like when you are cooking. I've posted tons of advice on here about training outside. Just search for Loki & house train
Trust me, you don't have to settle unless you want to.