Hey Nuno Alvarez
Regarding your issues of "suboptimal" bet sizes being chosen..
The reason it doesn't choose a certain sizing, although you gave it the option to in the parameter settings, is because of how close together your sizing options are, and your "merging threshold" probably being set to the default of 10% or 12%, or whatever it is.

So, if your bet size options in the tree are 10,15, 25, 2e, AND you set it to a 2 bet size strategy, the algorithm will build that 2 sizing strategy as a Small and Big bet.
So, in your case, the big option is b50. And since b25 and 2e are being merged together, it finds that 2e is very close to b50, so it chooses the next smallest bet size option, based on your merging threshold.

So, if your bets are within 5% range of each other, but you want them all to be available / considered in your solution, you need to set your merging threshold to 5% or lower.

You can browse through the "Tree edit" section at the bottom to see what bet sizes the algorithm considers on each street, based on your set merging threshold.