That are good questions, and basically the same for every green mode user.
For the balancing part: I usually set scheduled balancing to 10 days during winter. In Summer a new feature was added as well, called “opportunistic balancing”. That is, if the system notes a super good opportunity to balance (high solar, low consumption, super cheap grid) it can go for balancing earlier than the schedule and consider it done for another 10 days.
That greatly avoids balancing to potentially fall on very bad days, where you then need to buy 80% SoC from grid at potentially high prices.
Your observed idling mainly depends on solar and consumption forecast: When you look at your prices, from a scheduler point of view, there is basically a single truth:
It is always preferable to use battery from 12-20 today and tomorrow. So, planing at any time should favor to use battery in these hours, and let energy be taken from grid 20-12 if there isn’t enough solar to cover all.
How big is your battery?
What I would probably do in your systems case:
I would fake “half a cent” cheaper buy prices from 10-12. Then, any planed buying from grid should take place in these two hours, guaranteeing that as much solar as possible has been charged upto that point, and even during these 2 hours, all solar eventually available will be charged for sure by contributing to the charge rate with whatever is possible. (Or raise the hours 20-10 by 0.5, to get actual purchase prices, when charging is done 10-12; if two hours are not enough, make it 9-12 etc)
That should greatly reduce any (eventually false positive) idling during night, because the scheduler kinda would think:“No matter what, the cheapest opportunity to buy is right before peak-prices anyway”