14 week old puppy, next steps in house training?

We have a 14 week old Maltipoo puppy and we've been working hard on housetraining since bring him home at 8 weeks, he was trained on pads from the breeder and we started with them and going out very often but in the last few weeks have gotten rid of the pads and were just doing outside (every 2 hrs or more if eating/drinking after naps).
We have a very open house floor plan with carpet in most rooms so he's either in his playpen area (hardwood floor) or on a leash in the kitchen area which is also hardwood. After he goes bathroom outside we either continue to play outside or bring him in to play on the carpet (no accidents) with us for 20-30 min before putting him back in his playpen or kitchen area till his next bathroom break.

My question is when and how should I go about giving him more supervised freedom, he does bark or whine at times when he needs to go out but it's hard to tell at times if its because he really needs to go out or he just wants to come out of this playpen and play with us, there's been times I assumed he just wanted to play but then he went pee on the floor after being out 30 min prior. I'm feeling bad he's confined more then not, from what I read most dogs are not good at telling you they need to go till 6 months, is it better to continue this routine till then? He does great in his crate overnight since day 1 and sleeps from 10pm-630/7am without a peep, should I be crating him more during the day vs using the playpen? My husband works from home so is able to take him out often and he doesn't like the idea of a crate during the day but could that be keeping him from learning to "hold it" longer? Thanks!