less drop chances only means that caps/drop and caps/egg are better, not that you'd get more drops,in fact, you'd get less caps since drops are now scarce
let's assume that drop rate are 33% for eggs, 33% for caps, and 34% for nothing, and we'll assume that the RNG chooses 1 of the three choices at the same time (this is highly important).
since you battle 19 digimon in the 60e (4*4+3) the average drops would 19x33%=5.7, that means you get something like 6:4, 4:6, 5:5 most of the time.
in the 30e however, the drop chances are lower, the drop limit is lower, and so is the number of enemies, which is usually 11 (2*4+3 bosses), we'll assume that the drop rates remains unchanged and the drop limit is 5, we'd get 11x33%= 3.3, which meand drops would mostly be 3:2 and 2:3, which would mean that 60e and 30e have nearly equal drop rates if you play 30e twice, but since the drop rate does indeed get reduced by an x%, the 60e remains a better option than the 30e
the problem with the drop rate is in how the game makes the choice, something that I mentioned as highly important early on, s far as I've seen, eggs drop higher that caps, this is most likely due the way it works, I think that the game performs the egg chack first, then if that check fails, it attempts the cap check, so if an egg result happends, the cap doesn't even get any checks, so the egg drop has to fail and the cap drop has to succeed to get a cap, thus allowing the egg drop to have the upper hand