it may not seem like a difference: "machines seeking for, and then pulling power out of an e electrical grid" vs "power poles pushing power into any machines within their service area that are not already fully powered", but computationally, it is different. the first method greatly taxes the CPU because machine 1 searches for a pole, finds power, grabs power, but does not communicate to machine number 2 that there is a pole nearby...so machine number 2 also has to search its entire area until it finds a pole that can supply it with power.
it may sound abstract, but....when another modder/factorio enthusiast pointed me in the right direction, it was a pretty quick fix to just tune the electric poles way down....and then all the performance issues were basically fixed.
....but the way the tesla coil was invisioned....it isn't MEANT to connect to other tesla coils. so i'm not sure what the best solution here is.