Well all I can say is how I did it for my crew they went out just about every hour on the hour. praise for first week and then every two hrs for a month during the day except at night just once like from midnight to 6 am if they were at least 4 months of age. Feeding watering, pooing all on a schedule I wrote down to watch when say I fed at 12 and 6 they pooed or peed at 2 and 8 or whatever the case. I use a crate open kind to train and keep them safe from wires and such until I learn their habits and what to expect. they were only in it when I couldn't watch them. Now on occasion when the crates are up they go in on there own because they like it . I keep them acclimated incase need would arise such as fire, flood, travel, vet emergency, it may not be as stressful when they are caged at vets and so forth. I am a very very loving owner but believe a companion needs to be trained as a child would of that same age! babies are in cribs, do not roam un attended in streets or unsafe areas neither should dogs. maybe that would make it easier for you to see what I mean. Crating for long hours can be cruel especially to a young dog but training is the best thing you can possibly do to keep you and your dog happy and safe. I have trained not using a crate but find it much easier especially when I need to sleep and want my dog safe.
After a long walk the puppy may want a place to rest he feels is cozy and his, dogs were den animals. I put something of mine that cannot hurt them in with them. I spend time getting them used to crate open door at first, treats and so forth until it is comfortable for them. Then short periods of time 3 minutes, 10 minutes until finally an hour.
All I can suggest is what I have done for many many years, I hope things work out well for you both. Exercise and puppy social skills are the best you can give him, a bored JR as you know is a handful! Puppy classes are great as is any socialization with other dogs, children, cats, bikes, car rides, long walks.