Question Regarding (Modding) Dual Class and Kits, and Weapon Proficiency

In regards to fighters, when they Dual-Class into another class with lower weapon proficiency limits, like a mage, once they regain their fighter levels they can now achieve Grand-Mastery in any usable weapon type (so no swords for clerics) and style. In an upcoming mod I plan to create Fighter which Dual-Classes into a kit (mage)--which is possible using the correct code. However, I wish to put some limits upon the number of max proficiencies and types of styles that this Dual-class character can choose--like only 2 per weapon, and no access to certain weapon styles. My question is: is there an easy way to achieve this within this engine? As it so happens, the Dual-class character will simply use the fighter Prof. limits, so changing the (mage) kit weapon limits will only affect the character before it regains its fighter levels. Further, I am aware of the mod that makes all Dual-Class characters use the limits of their second class (Enforce PnP Proficiency Rules on Dual-Classed Characters by @subtledoctor), but I do not wish to change all dual-class characters, only this one (mage) kit, which the player dual classes into.