I think you could still use the single LED and get more feedback to the user.

Stealing from something else.

You could have a LED flash flag that will allow you to get a point of reference. Think Morse Code sort of.

You have a starting “marker” of one flash, then 2 flashes repeated 2 to 3 times, this gives the user a starting reference, then the LED can flash “numerical” patterns or codes, maybe once, then the starting “marker” is flashed again to alert the user to the end or the start of the sequence again.

I realize there are power conservation issues and other things, but maybe there is a group of codes ever 1 minute in addition to a “heartbeat” to indicate what the meter is doing.

I have PLENTY of ideas if you want to get deeper into this.

j