This is actually intended in the dice roller, at least for now. We by default start from a place of not restricting players / groups from rolling whatever dice they want - there are homebrew and “table stakes” things that happen during a game that we can’t account for, where a GM could say that someone could roll more than six for a specific thing because of various factors.
Having said the above, that is just the starting point, and we plan to add some additional preferences / options around how it works in the future. The idea is we would want to have a “speed bump” and not a wall, and once we get to that point on our list, we’ll have a default “The Rule of Six” preference toggled on that players could toggle off for “rule breaking” rolls if they desired to do so.