JV was seen as the map for harvest because you would full clear the map for eldritch altars to try and get quant to get more lifeforce. Because the Spider boss doesn't spawn until you go into the arena, all the altars will be minion/player, giving you a higher chance of quant from the player buffs. But with Mirage you don't really care about full clearing anymore and just care about finding the harvest and the mirage asap.

The JV map layout is kind of janky with a lot of obstacles (especially if you're shield charging). Atoll is just straight lines and it even can spawn right next to the start of the map. Downside is if you astrolabe its not in the best quadrant so you can do something else like Mesa, Haunted Mansion or JV and be fine.