Good to see Livo. It very much is something that can be tinkered with and still get pretty good results. I've had similar experiences as you mentioned.
1. Chicken
I now just dump in a pack of skinless, boneless thighs whole. Much less fall-apart and no need to chop raw chicken, so less clean up.
2. Consistency
I found that switching to canned crushed tomatoes instead of diced gives a much better result and no need for blending. Just this week I tried rinsing out the can of tomatoes with 1 cup of water and adding to the pot but that made for a very thin result, so I ended up blending.
3. Cayenne
Agreed. I use 0.5 tsp extra hot chilli powder and 0.5tsp Kashmiri. Much better. I also find adding 5 or 6 thai chillies, sliced lengthwise after the pressure cook work very well, although not when cooking for the missis.
All in all though, as a simple technique to get a decent curry out, I'm finding this a great basis for experimenting. Glad you had a positive outcome. More to follow.
Robbo