Congrats on reaching CL2 and I believe that's the way to go. But you don't actually have to stay at CL2 for EOS, you just need to reach it once and then you can drop down and play in CL3 if you want. The snapshot now is higher league obtain and not league position at EOS.

I just restarted playing the game after a while and grinding for Novice chests in the Silver league can be very satisfying. I use satisfying vs rewarding as it's great fun opening 15+ chests daily, like a scratchie. But the chances of getting anything rewarding is almost nil, which is fine as that's expected. I believe I opened around 100+ daily chests and the best card I got was a rare and one triple digit DEC.

How much DEC do you get in one chest, on average? I expect that all the DEC you are getting would be more than sufficient to buy the common cards and potions that I am getting. So I think for players who own lots of cards, it would be better to push for a higher league position then to grind it out in the lower leagues and rent their cards out.