I love the new pole coverage, but circuit wires won't reach now. Could you make the circuit wire length longer to reach between the new pole distance?

I haven't modified the Circuit Wire length.
They will always allow connections between like Power Poles using the smallest of the 2 wire connections.

i.e. Substation to Big Pole will use the Substation max distance.

As for connecting from poles to assemblers etc, it's remained the same as Vanilla, 9 tiles Diameter.

If the poles aren't connecting could you please provide a screenshot/Blueprint String.