can't see how it's gonna get better unless the chain stretches. will it even stretch being so thick?
when we say a chain stretches, we're thinking that the chain plates have elongated from tension. however, the truth is that its the pins in the chain getting worn down over time from friction (insufficient lube, dirt and grit getting worked into the area) that makes the chain longer. Hence its why its important to lube/WD-40 flush the chain then properly re-lube afterwards.
WD-40 can be used to clean out the old lube along with grit/sand etc (if you dry it properly afterwards before lube), and it's important to work the new lube into the chain so it reaches the pins and rollers properly, instead of just having lube sit on the contact surface between chain/driver/sprocket.