Pros and cons of LUKS keystore locations

Sorry, @ElvishJerricco, need a bit more help before I can set up my system. What are the pros and cons of having the LUKS keystore we were discussing (say 4MB in size) as its own partition vs on the zpool? For the former, can I not simply order the zpool import and key loading after the LUKS partitions are unlocked, or is that done automatically?