I just noticed a very slight issue with the pactsworn knight archetype. As per the side note a samurai can take the archetype which is awesome. However, the archetype does not swap out the mounted archer ability of the samurai. I was wondering if there could be a caveat added into the bonus feat ability of the pactsworn knight write-up that specifically allows a player to swap out the ability for another combat feat/occult feat/binder secret.
I don't think so. That page is basically full, and I don't like the idea of making a trade only for the alternate class.
It'll still be a nice perk to have if you decide to bind a spirit with a vestigial companion you can ride, though!
Because the archetype changes one of the core features of the class I personally don't see the trade being an issue. You are removing the mount feature of a class, why would you not also remove the other, now superfluous, class abilities which augmented that feature. Although I can understand not making the change as the page is full. Personally this will be addressed in my own games should anybody choose to use this archetype.