In regards to the new tree functionality in Mathematica 12.3, apparently the display is collapsed/summarized when an element has more than 10 sub-elements, so what I was expecting to be displayed as 11 is replaced by a <<1>>:
RulesTree[1 -> Range]
is there an way of preventing this to display the full tree?
UPDATE: I have found that there is a symbol Trees`$VisualizationMaxChildren which is protected. It can be unprotected and changed to avoid the truncation. I'll leave the question open as this is kind of a hack, but it works.