Era Leveling currency bottleneck

I noticed this era that Era leveling currency has become a complete bottleneck if you take you units past 3 stars. I think this is bad game design on account of the fact that this leveling system only exists for 90 days. Give us enough currency to level our characters as far as the materials we earned can take us. Maybe put a little bit of currency alongside each material drop in coliseum. Bottlenecks make some sense in the main game. But not in an area of the game where the entire goal is to take these characters as far as possible in just 90 days.