Get a fresh set of plugs for proper testing.
Assuming the rings are ok ( good compression reading only tells you the valves are seated ) there are only three places from where you would get oil into the cylinder head.
White smoke on de acceleration ..... hard or worn valve guides and seals
White smoke at cruise and NOT under load... head gasket oil gallery seal failure ---- will only affect 1 or two spark plugs.
White / blue smoke under load at low to mid acceleration.... Ring wear. will also see when coming back to idle.
White blue smoke under hard acceleration ... bad turbo seal / impeller