Right now shrine donations are very "mathy" if you don't care to lose currants. Spending emblems is a vast improvement, but I still feel compelled to get my calculator every time I donate to a shrine. There are two problems:
1) Favor past an emblem breakpoint is discarded.
2) Emblems are only ever worth 1000 favor when used on a skill, so shrine capacity over 1000 is lost if you overdonate.
You can lose SERIOUS amounts of favor if you don't check the shrine first, or don't get out your calculator and donate to a very precise point - either just shy of the emblem for training or right at the emblem if you're working on icons. It seems to me that this is not very intuitive to have in a game. I have two suggestions that would make things much better:
1) Roll shrine donations over past emblem breakpoints. If I put 1000 favor into a 1200 capacity shrine at 600 favor, 600 is applied to the emblem, which pops out into my hand, and 400 stays in the shrine towards the next emblem.
2) If a player is going to donate enough to create an emblem, the shrine should ask for confirmation. That way a player wanting to spend 1499 points on training at a 1500 point shrine isn't stuck with an emblem only worth 1000 if they miscalculate.