My K-1 prime kit is usually something like:
DFA50, Rokinon 24, DFA100WR
Where the DFA50 (or, if I'm feeling like saving weight, the 40XS is acceptable in a pinch if you don't care about corner sharpness) will be my "walkaround" and I'll swap to the 24 or 100 as the situation calls for it. On a trip two days ago I took the 40 instead of the 100 as I was planning on the wider end; didn't end up taking the 40 out but it's so light it often rides along because why not... Sometimes I'll swap in a Helios44 or Takumar 55mm if I'm feeling like a break from modern glass.