So I did a try with only white gluten free flour and of course the rice sourdough that you can see on the photo. The Rice sourdough was very strong and I was very happy with it. Its development can be done only if I managed to build a environment of 30C, which I do in my oven and it worked perfectly.
But the result of the white bread was not conclusive. The flavor is good but the "bread" is more a heavy pancake.
I mixed some poppy seed to make some effect.
The mock rye bread was still ok after one week and when getting a bit dry it had a more stronger bread flavor than when it was fresh and was more like a mud cake.
I'm keeping a pretty big amount of the rice sourdough in my fridge to continue with experiments next week.