Hey there,

I was wonderin, if there is a way to do the lvl 42 challenge quest, now that I've finished the subsequent quest Turret Defence Challenge #2. I'm well beyond lvl 42 and the trader/terminal thing in Grubby Cave only gives me the option for the lvl 52 challenge mode.

I'm fairly certain the two challenge quests for this are to do each course in challenge mode, the one in Grubby Cave and the one in Temple of Innovation. Challenge mode specifically scales enemies to your level, which is probably where 52 is coming from. The quest is level 42 because that's around where you would be when it first becomes available.