It would seem like other values aren't vanilla defaults either, like big pole area.
Yes, that is correct.
You don't have to give them max limits like 4 either like it currently does.
Indeed, but I like (and I'm going with) the ideea that high/medium (voltage) poles should be mainly used for transporting energy, not for supplying it.
This mod doesn't seem to be made for game balance anyway but player options.
Please check my other reply (see above) about the logical reasoning behind the default values.
Indeed, the mod is primarily targeting player options (which should be able to configure the vanilla values if they desire so), but also, in my opinion, its default values provide a more balanced (between reach and supply area) approach to electric network planning compared to vanilla.