Hi @WereAllMadHere, thank you for sharing your story. It sounds like you have got a really good system in place and I imagine it must have taken a lot of work to get there, so well done! Managing feelings and boundaries can be really tricky.
One tactic is to give information about non-negotiables (bedtime, brushing teeth) when he is feeling calm and you aren't boundary setting. For e.g. normalising that some of these tasks might be boring or things that we don't want to do but they are important for our health and we need to do them. Then when it comes to setting those boundaries, you could remind him of the conversation that you had which helps to acknowledge how he is feeling but also remind him that this is one of those times where we have to do things we don't like.
Another tactic that is important with setting boundaries is to communicate the consequence very clearly beforehand and/or to let your child help choose what the consequence is. It can help them have some control over the situation and can reduce the feeling that things are unfair.
These might be things you have already tried so please let us know! There are also some Australian based websites such as Raising Children Network and Emerging Minds which might also have some relevant information for your situation
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