Daytime crate training tips?

Hello! I’m seeking any input on crate training during the day. We have a Golden Retriever puppy (3 months old next week). He is fine with sleeping in his crate through the night without crying and can hold his potty in fairly well for his age.

We are concerned about his crying/whining in crate during the day time. We’re afraid when he gets older/bigger it’ll get to a point where neighbors (we share walls) might be able to hear when he develops a louder voice. Eventually we’d like to open our windows when it’s hotter too.

We have to enforce nap times. We’re trying to stick to the “1 hour out, 2 hours in crate” method as closely as possible (sometimes it’s closer to 1:1 or 1.5 because of work - I WFH but my downtime can be unpredictable). When we tire him out (activities include chew toys, wrestling/playing with our other/older dog, walking, puzzle/slow feeder for meals, trick training), he mostly naps right away. However, he often wakes up after about an hour and will cry. He especially cries (at least 20-30 minutes) the longer he is in there (usually the 1.5-2 hour mark). Sometimes he settles momentarily but then he will cry again, which is often in intervals. We know it’s for attention rather than needing potty.

His crate has a towel that smells like us, a Snuggle Pup, 2-3 toys. We associate high reward treats in there, give him Pupsicles/frozen baby carrots/licky mats/kongs to occupy him during crate time, feed meals in/by the crate. We play white noise and close the blinds. We have a crate cover for the sides of the crate but we don’t cover the front because the breeder recommended to not use a cover because she didn’t use one when she had him, and he gets hot really easily. We tried to cover all sides during night 1 but stopped with breeder’s suggestion (crying at night was horrendous at the time). We tried a playpen but it didn’t help. We have tried giving treats when he quiets down and we also wait 1-2 minutes of being in a “down” position + quietness before we take hum out (he rarely can go any longer). I’m thinking maybe we need to do this last part more with shorter intervals of crate time?

Is this something he might grow out of eventually? A trainer we consulted with seems to think so. Should we do anything differently? I do believe it is attention-seeking and he just wants to be with us. We are not planning to let him free roam the house for a long time so we are really hoping he becomes accustomed to the crate/being alone whether we leave the home or when we need to crate him during chores inside the house. Any advice or sharing of any experiences would be greatly appreciated!