Flexible Custom Baseline Activity Level
The current custom option is a flat modifier, which is fine for weight maintenance but would need constant readjustment for large weight changes. It would be nice to be able to set the multiplier for a more flexible result. For example, someone with mobility issues will have a lower activity level than the default sedentary multiplier and may want to "set and forget" their level to BMR x [custom multiplier lower than 0.2] instead of recalculating the custom flat value every time there is a substantial weight change.