What happens with existing entities that currently fit in a 2x2 grid that would be up alongside other entities? Do these poles just get deleted or things break? Seems like a significant change. Does the entity size get longer wire reach too?

In regards to the new 2x2 -> 3x3 update

Existing huge poles continue as they were. If you pick it up and try to replace it, the new placement will be on 3x3 alignment. The wire length is adjustable via startup settings, up to 50. I could extend that to a maximum of 64, if you are asking for the change.

Version 1.20.3 has been uploaded, it adds a startup setting to enable the 2x2 huge electric pole.