Advance Weapon Training (Weapon Master + Brawler + Item Mastery combo) question

Question

For the people that doesn't know the combo, here's the link to Cartmanbeck’s Guide to the Iron Caster; all credit goes to him.

The scenario is this: the weapon master archetype gains weapon training at lvl 3, and he has this benefit:

Special: Fighters that have the weapon master archetype can select this feat beginning at 4th level. The benefits of a weapon master’s advanced weapon training options apply only to his selected weapon rather than all weapons in the same fighter weapon group, and he can’t select the weapon specialist advanced weapon training option. A weapon master can select this feat as a bonus feat; if he does so, it doesn’t count for the purpose of the requirement that it can be taken at most once per 5 fighter levels.

in lvl 4 he picks the Advanced Weapon Training as a bonus feat, and at lvl 5 take a dip into brawler and gain Martial Flexibility.

The question is if with Martial Flex. one can take again an advanced weapon training feat ignoring the clause of the 5 lvls, despite the fact that it doesnt gains it from the fighter bonus feat as this implies

[...] A weapon master can select this feat as a bonus feat; if he does so, it doesn’t count for the purpose of the requirement that it can be taken at most once per 5 fighter levels.

A player of mine is using this and im inclined to, if proves illegal, let him play it anyways. But I need to know if it is indeed legal. Thanks in advance!

Answer 1

It works.

As you note, the Advanced Weapon Training feat says:

Special: Fighters that have the weapon master archetype can select this feat beginning at 4th level. The benefits of a weapon master’s advanced weapon training options apply only to his selected weapon rather than all weapons in the same fighter weapon group, and he can’t select the weapon specialist advanced weapon training option. A weapon master can select this feat as a bonus feat; if he does so, it doesn’t count for the purpose of the requirement that it can be taken at most once per 5 fighter levels.

So as long as the Weapon Master selects the feat as their 4th level fighter bonus feat, that bonus feat does not count towards the restriction of only being able to be taken once every 5 fighter levels. This would allow them to use Martial Flexibility to take the feat, assuming that they haven't done so with the feat slot they are granted at level 5.