Thank you Peter.
That sounds like a good workaround.
I am simply thinking why, the ribbon manages to split the text by itself on some occasions when there's no code added, and not in others.
And like I said, even the choice of the icon has an impact, although the icons used on the 2nd goup in my snapshot are smaller than the ones used in the 1st group, the 1st grouip is properly aligned using the 2nd line for the text, while the 2nd group is expanding to the right. If I use the same icons as in 1st group, then text in group 2 is also split into 2 lines automatically.
This is why I was kind of hoping that they would be a property allowing me to control and set the 'width' of each one of the items.