oh that's interesting, so let's say i grab the node that says that burning from critical strikes deals more damage, this means that if the explosion is a crit the burning calculation will be affected by this mod in total, and not only the burning part that cames from crititalc hits?
No. Each arrow calcualtes it's explosion hit & ailment damage separately. Only those which are crits individually will calculate their damage with that modifier, because that modifier only applies to damage calculation for crits.
When the individually calculated damages are combined, if any are a crit then the explosion as a whole will be considered a crit for on-crit effects, but this cannot affect the damage calculation in any way, because that has fundamentally already happened before that point.