Let's say you get 500 max one day. The next day, the shop will update up to a certain amount each day until it hits the max amount. So if it adds 100 per day, then you need to wait until after 5 days before you get 500 in one go.

Let's say you have 100,000 summon coins and 1000 group coins, those coins are left alone while arena, survival, and ranked are all considered to be moved towards sun or moon coins. So after the update, summon and group coins are left as it while how many coins in arena, survival, and ranked are put together in either sun or moon coins meant to be spent on the scroll system or the item shop.

That was like that in China but they used survival as well in a later update.

Yeah I'm aware of that. Just looking at the end result (well what china has)

I had to double check since I stopped using the coins for the scroll system. The update was the design of the survival coin (it's now pink in China) and some ninjas were switched from using survival coins to moon coins and vice versa.