Recessed spotlights for general lighting

That may theoretically be the case, but practically I have never had a problem in that regard. I extensively use low dim values <20%.

I use MDT dimmers with the lamps mentioned above.

It is no wonder that you have no problem with it, because you use high-quality and price-wise carefully selected products that are compatible with each other. To make a general recommendation from this is like a Porsche driver saying: "You can always take the curve at 100" and forgetting that most cars have different chassis characteristics. Whoever follows that without knowing the conditions will crash out of the curve.
Therefore I also wrote: "You can confront the PWM risk with a lot of money if you want to dim over a very wide range." That is what you do at home. An MDT dimmer quickly costs 200€.

Warm white panel lights fit perfectly into the 180mm boxes. They have about 12w and provide sufficient light with your installation scheme. They are available from cheap to expensive from all kinds of suppliers. I have implemented it this way throughout the house and would do it the same way again and again.