please help fixing my portugese sauce (a kind of korma-like non-spicy curry sauce served in hk and macau)
At a guess, though you need to clarify - not 'rich' enough &amp; probably thin in both flavour &amp; texture, with a grainy edge. 

Yoghurt adds acid, rehydrated coconut is absolutely no substitute for coconut cream.

Rehydrated coconut won't provide either the flavour or the texture of coconut cream. It will leave the sauce thin yet slightly 'gritty'.

Yoghurt is going to add an acid edge that this sauce doesn't need.

Pressure-cooking rather than frying off in an open pan then allowing to simmer will keep too much liquid level in the sauce, exacerbating both the above points.

Once you've corrected those, if you want 'more curry but no more heat' then try adding some garam masala.
I'd also add garlic &amp; a little light soy sauce.

If you're not having this with the traditional chicken, then you're also missing the ingredients the chicken would have been marinated in - soy, shaoxing, ginger - so maybe some of those too.

You're also missing the oil that the frying would have added, but if you don't want to add that, the coconut cream will have to be the only fatty mouth-feel ingredient. Lose all the fat, lose the mouth-feel of the sauce, I'm afraid.
You could cut the coconut cream to coconut milk, but I think that would still come out too 'skinny' in taste &amp; texture.

Personally, I'd double the curry roux, but I just like more kick than traditional in this type of sauce ;) It will help the texture, though.