Precast is most often fast cast for spells, JA enhancing JSE for the respective JA.
Midcast will depend entirely on what it's calling that midcast set for. Phalanx+ for a midcast.phalanx, ehancing duration/skill for any other midcast.enhancing.
ctrl+f and search enmity, dump your enmity sets in these areas but keep in mind you may have a standard enmity set, a SIRD enmity set and so on. Those you would modify according to what type of enmity set it is named as, prioritizing SIRD/DT etc and adding enmity in where you have room.
So most likely my enmity sets will be midcast? I think that’s where I am lost as again I am not well versed in gearswap. And my tanking set will plug into engaged? I think part of the problem is I don’t have a ton of gear sets. I do have a handful such as enmity, PDT, MDT, and fast cast