I'm going to need to know where we will set the LDO voltage in order to pick iadj components. Am I supposed to decide this? Are there any mcu issues to consider in this? Parasitic drain etc?
Things I can see (neither very relevant probably) are:
1) If we ever want to consider adding software frequency control or possibly other things, more is better.
2) However, there is an issue with 1S battery setups. Normally you wouldn't use the LDO at all in those, but we are driving iadj off the LDO. If you drive it off the battery you get voltage sag right from the start on a current controlled buck, which is just silly unfortunate. One possible fix would be to still include an LDO and set it to about 2.8V (or use a tinny85V and go lower yet, like 2.3V). I don't actually see that this effects decisions now though since 1S battery will need a different voltage divider anyway. Also using a buck from 1S battery seems not so useful to me anyway.