Currently only having the ability set one log interval assumes you need or want the same update resolution at all times within a 24h period.
If solar logging is the main thing you are tracking within VRM there is little reason to have the most frequent minute updates happening outside of PV production hours but desirable during it.
Even with tracking consumption, people use more power with greater variance during waking hours as they are actively affecting the loads. At night loads are typically lower, more consistent and predictable so a good reason to have the ability to set different update frequency during waking hours and nighttime hours.
The main consideration is one of power efficiency by reducing communications that don't offer any real benefit. For limited wireless cellular data plans it would also be very useful. The small communications can be charged as a minimum block of data per communication so lowering the update frequency right down during certain hours can reduce the total number of communications but not mean you have to compromise by setting a lower update frequency at all times.
Form the server end If a good percentage of people were to drop their current update frequency down during night hours it would reduce total requests on the servers and that can't be a bad thing either.
