The last thing I'd do is to defend the rules book. There is quite a lot of it which makes scrutineering an unnecessary complicated task. Giving the dimensions of aerodynamic devices relative to tires and to the ground is bullshit as it is leading to the situation we are discussing at the moment. If you'd just give a max. width for a front wing everything would be much easier. Or just not giving any limitation to the width of a front wing would make it even easier and the teams would have to really think about how wide to make it. If you give a max. width all you have to do is to build a wing of that width without wasting any thought about it.
In the current situation the only possible way for the teams to deal with it is to leave some safety margin to avoid a situation like this year's FS UK.
The rule T3.5.5 is still in the rules book as the years before. The only way to interpret it in a way that will somehow work is to only apply it if a frame member which is defined in the rules is made of multiple tubes. For example the triangulating member of the front bulkhead suppert. Usually you can't find a straight single piece tube which is fulfilling that rule, instead you have to combine two tubes which are together that member. Therefore it is considered as a member in the primary structure made from multiple members and needs to be triangulated. It's not exactly according the wording of the rule as the rule would more or less apply to any node in the chassis, but it's the only way how to handle it in reality.