I tried Masters League farming back at early TH9, once I had loons and minions maxed. The DE income up there is crazy, and you can make some decent gold too. Both loonion and giant-based armies should work fine (I recommend LavaLoonion). If you do use loonion, I strongly recommend boosting rax and SF, because unboosted loonion is 48 minutes to train, and spells are important up in Masters. The league bonus is more than double minion cost if you're doing 24 loons and 50 minions, and I went for at least 2k DE that I could get, but after a bit of searching you can find 3000+ DE that you can get from a DE storage in 1st or 2nd layer. That combined with loot bonus is amazing DE. So to answer your question, to farm your royals, Masters League is more than worth it, and there are a lot of full gold storages there, so you'll get some walls done too.
By the way, you said you're getting good loot with BAM in G1. I haven't tried G1 in a while; do you think it's better than G2? I'm the "lazy farmer" type of guy; just nexting till I find a collector base, which is pretty monotonous and boring, as you said, but it does the job
Good luck!