https://youtu.be/RcVcNdXtQYo
I made 2 camera gopro style adapters for 2 egg cooking timer

One bought at https://www.action.com/fr-lu/p/minuteur-de-cuisine-4/
Put in directly on timer without any other manipulation and then push your camera support on it

an other classic eeg cooking timer. you just have to remove the cover and place the adapter

The camera and the timer are very stable