there is a hidden tunnel under the lava that leads to quavonis firetail. here are some locs:

wall in quavonis area: 1284.09, 1421.24, -147.78
quavonis platform: 1069.79, 1591.41, -147.26
mouth of tunnel in quavonis area (under lava): 812.02, 1599.08, -292.24
mouth of tunnel in main pof area (under lava): 448.54, 1269.06, -403.52