You are doing 2 hours per day with your son in the playroom! Good for you, that is so wonderful! Yes, I agree that having in the playroom more will be a great longer term goal which could really help this situation. The essence of it is that our children crave control and search for predictability in any way they can get it. Therefore, I would use plenty of explanations whenever you are going to throw anything away and a with a little bit of preparation and taking more time on it, you will help become predictable and manageable for your son.
For example, if you see a broken toy around the house, first mention it (e.g. "Oh, it looks like that egg is broken") and leave it where it is for a day. Perhaps the next day you can tell him what will happen (e.g. "I think I'm going to throw that egg away tomorrow because it's broken"), then when you finally go to throw it away the next day havie him be a part of it (e.g. "You go and get the trash can and I'll throw it in") so he feels in control. If he helps and is open to you doing this, give him a celebration and tell him how wonderful he is! Ultimately, if he says "No" at any time that he doesn't want it thrown away, then I would honor that and keep working in the playroom, with a focus on giving control and working on flexibility goals.
If you feel the situation is more of an issue at other people's houses then limit your trips there right now and keep him in your house as much as possible. he will have much more control in your home than in others.
Focusing on your own attitude at this time will be key. If for example it's too late and he sees something that has been thrown away without him knowing, instead of feeling frustrated, fill yourself with calm, comfortable and relaxed thoughts, knowing that he is doing the best he can to gain control in a world that's out of control and you just being the calm in his storm will help him calm down and also model how people are attractive and easy to connect with.
All the best!