Separation anxiety - 1 visit a day better than 2?

I have a 4 month old golden retriever who is showing signs of separation anxiety. He is fine being in his crate when my SO or I are there, and sleeps well at night, but starts crying and barking like crazy if we leave. We are slowly working on him getting used to being alone (stepping outside for 1 minute and coming back in, etc), but it doesn't seem to be getting better. We can't even take the trash out without him freaking out. He has also started to cry if only 1 of us leaves, even if the other person is still in the room.

Currently, we bring him to doggy daycare 2x a week and than have him stay at home 3x a week. I have a dog walker service come by twice during the day to let him out. Based on neighbor complaints, I know he will cry for a long time (over 30 min at least), before tiring himself out and falling asleep. Since he does this each time someone leaves, I was thinking it may be better to only have the dog walker come once a day so that he doesn't have to go through the leaving process and settling down an additional time.

Current schedule: 8:30am - I leave for work, 11am - dog walker comes, 2pm - dog walker comes, 4:30pm - I come home from work

Proposed schedule: 8:30am - leave for work, 12pm - dog walker comes, 4:30pm - I come home

Since he is 4 months old, I think he should be able to hold it fine. He will hold it from 11pm to 7am overnight. Any advice/thoughts is appreciated! Does anyone think this will help or would having the dog walker come twice a day actually be better for his anxiety?