4 times 30 is 120.
Whoops, I didn't go back and edit that post too. Thanks for catching that, I've updated it now. Back to the point, let's go back to the assertion I was first replying to:
You can get 200SG/week pretty easily
Clearly 4 times 30 is not 200. 200 requires 4 times 50, which means a top 10 finish and that means being one of the three best parties on all four leaderboards. So... pretty easily? Absolutely not lol.
The two ship leaderboards are simple enough to get 60 SG a week. The universal ones perhaps a bit tricky. But let's stick with 3 hours for four runs if you're lucky enough to not need to wait for parties to form, and suppose that gives 120 SG for the week.
In that time you could get some 25-30 battle arena games in, which is more than enough to recover from the monthly drop from Legend to S1 (or if you're below that, rise up the rankings which gives even more SG in promotion bonuses) and get at least 50 of the 100 SG available from the BC exchange every week on top.
To suggest challenge mode gives more SG or that it gives it faster or more easily than battle arena is frankly daft. Unless the Miles Master exchange starts offering weekly SG using challenge miles, there's no contest.
And you might think there's no contest anyway because people can do both. But not everyone can. For those of us with only a few hours each week to spare between campaigns, events, missions and non-PSO2 activities (that dreaded life thing) we may only have 3 hours to play for SG. Or we may simply only be willing to spare that much time every week so we don't get bored. Either way, as things stand challenge mode often isn't getting considered because it's unrewarding.