ABRP gives impossible plan (dipping into negative SoC) if steep hill descent is shortly before destination

ABRP can create plans that would have the driver stranded. This can happen if the destination target SoC it quite low and there is a lot of elevation descent shortly before the destination.
Even if there is charging, it will propose to leave with too low charge. Clearly ABRP only checks the SoC at the destination is accoring to settings, but does not make sure it never goes below that (as a safety margin) or even negative somewhere on the way.

The issue is not specific to ABRP on any particular platform, but most likely stems from the route planning backend.

Example plan:

https://abetterrouteplanner.com/?plan_uuid=724c028a-40f7-494c-99c9-63cc81572855
This is a short route with a steep hill in between the start and destination points. The plan produced expects the car to reach -2% at the top of the hill, while regen then gives it back enough to hit the target SoC at the destination, which I set to 2% here to create the example. Even though charging is done at the start, it still suggests departure at too low SoC.

This is clearly a fringe case, but may in such rare occasions result in the driver being stranded. In the real world, most people will have ~5-10% SoC destination target, providing some resilience (unless they dip into their safety margin), but high enough elevation change (1+km) can still provoke this issue, especially with cars that have smaller batteries.

A proposed solution would be for ABRP to check that the SoC does not go below the “destination SoC“ anywhere on the way, since it clearly knows the SoC values along the route (that it displays when a point on the route is selected as in the screenshot). Then adjust the previous charging stops based on the lowest SoC point on the route instead of at the destination.