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No, and a % is not going to remain as a fixed amount of energy. It's going to keep moving and shifting over time. That's because % is not an amount, but a fullness ratio.
Simplified example: Let's say you did have 100 kWh usable. You could figure what 1% of that is. But in several years, let's say the car only has 94 kWh usable because of aging and degrading. 1% of that would now be less. The car will still show 100% whenever it's holding all it can, even as that amount changes over time.
You're also lumping in a lot of things that are not necessary an energy expense into what you call "phantom drain". "Out of Spec Podcasts" has a great new video on Youtube about how people calculate phantom drain wrong (