What do the flashing rates on an Elster REX2 electric meter signify?
According to the manual the arrow box arrow are real energy indicators
Of 3.2 Rex meter tech manual
They pulse at a rate proportional to the rate of consumption.
Each square pulse indicates 1kh.  each change of state on to off indicates 1/2kh.
The arrow toggles for each Ke
Left arrow energy received
Right arrow indicates energy delivered.
It said see table 2-1 for ke values per meter form.
Form 1s, 2s, 12s.   ke.1 kh1.0
Form 3s, 4s      ke.  0.01 HK 1.0
So it depends on the meter form
The different forms are the class meter 20, 200, 320 2 wire or 3 wire single phase and if there is a disconnect link.