Bo-ABRP's post in Still struggling with ABRP choosing suboptimal stops was marked as the answer
Thank you for this feedback - the issue has been found and fixed!
Technically, we the planner is an optimizer which optimizes a cost. The cost is usually total trip time, but we modify the cost to weigh in preferences and risks. This means that the total trip time may not always be minimized since other factors do play a role.
In this case, the bug was that we calculated the number of stalls completely wrong, which made Target look like a risky choice. When you add the charger as a waypoint, we ignore that risk. Now corrected!
Bo-ABRP's post in Who do I get higher arrival charge than specified? was marked as the answer
ABRP finds a route by optimizing the total time, charging+driving+overhead. Getting to a charger in a modern Tesla with less than 10% is usually not a good idea, timewise, so ABRP will typically avoid that. There is no cost to getting to the destination at very low SoC %, so it will always arrive with the lowest allowed SoC.
The ABRP optimizer is currently slightly granular and will typically optimize the time in steps of 5% charging - which is why it sometimes jumps from 10% to 15% arrival SoC if that turns out to be (slightly) better.