Scarface out of roundness for inline-ness for any compromise required. Tires are all slightly out of round and road surfaces also give uneven rolling round-ness, so feel and behave identically normal, but out of line can wear tires more, reduce mileage and if doing traction loss leans it can bias which way is safer or easier. I put tape patches on low spots and clothes pins on hi spots to help visualize where to relieve and where to take in tension, a whole bunch over weeks till happy with almost perfection. Once the real tension begins to build a dial guage may show a small dish in rim at each nipple location. Even tuning the last bit by tapping a row of spokes and tweaking, still better watch the side guage or end up undoing somewhat, again.