I have the same thought. See my todo point 5 here.
There are some complexity to it and all the edge cases would need to be considered.
E.g. 36 and 48 are only available in EPR mode. EPR mode has a keepalive, where it will exit EPR mode to 20V or 5V SPR mode if the EC does not sent the keepalive to the power adapter.
It will be interesting to see if a simple rule “EC to force it to EPR mode” everytime one plugs in a power adapter will work.
Another edge case is:
You have a 100W (20V) adapter plugged in.
You then plug a 240W (48V) adapter in as well. It is supposed to switch to getting power from the 240W adapter.
How does it do that without going via the 2.5W step.
One idea is to go from SPR 20V to EPR 20V, and then shift the EPR up in 100mV steps, until it gets to 36 or 48V. But that is a lot of messages, and 280 transactions over a slow CC bus.
We don’t have the schematics for the FW16, so i don’t know if it can deal with 100mV steps or not because the FW supplied EC code has never tried to do it.