Do we really know how close to round any cylinder bore remains as the block warms up? Particularly if there's a casting flaw that affects heat flow and temperature distribution (and hence expansions/distortions)?
"Oval" was the best word I could come up with to mean "not quite round". Not visibly oval or necessarily even a nice symmetrical non-round shape. You guys have a deeper level of engine building experience than me (I do have a little), but the thermal transient analysis work I did from time to time before retiring gives me a fair idea what might be happening.
'08 GT coupe, 5M, wheels, tires, pads, fluid, a few suspension mods . . . still almost stock height
'19 WRX, 6M (the "family sedan")
'01 Maxima 20AE, 5M (the spare and occasional winter driver)