Btw, my OCD wouldn't leave me alone so I decided to order red M5 screws for bottle cages from AliX to match other red bits such as chain catcher, brake callipers, valve caps etc.
They arrived and I tried to install one and it snapped! Part of it stayed inside the rivet nut
The rivet nuts are not of great quality but at least screws that came with the frame are (I'm guessing they are stainless steel by the hardness and weight).
So I had to drill the hole and use the tap and die set (luckily I have one for small diameters).
Lesson learned - don't buy cheap parts cause they may cost you too much in the end!