Tbh I am interested in all three types of mission. Been playing this game for nigh on 13 years now and I find a bit of variety in my PVE helps me stay interested rather than just doing the same type of mission over and over (which tends to bore me quite quickly and often leads me to extended AFK absences). I already have a few low sec stations with multiple level 4 agents in them but I have found them through the method you describe on dotlan, likewise a number of high sec systems with multiple agents in the same system, but rarely the same station - I’d rather not have to manually click on all 3,600 systems to find the answer I am looking for.
I did find the post below on reddit, but it says you have to use the static database dump and SQL which is frankly beyond my abilities; and like I say, I did have this spreadsheet before so I was hoping someone else knew where I could find it.
Likewise there is also this list, but looking at it, I think they are all level 4 high sec security which is a part of what I am looking for but not the whole. I’d rather be able to manually sort through all mission types in all security space (not just high sec).
 do appreciate your response though.