VC4 500 IDEX weird wavy bed mesh

Hi there! I just finished assembly of my new printer and it puzzles me. Here's the bed mesh I'm getting. This mesh has min of -0.365 mm and max of 0.076 mm (0.441 mm range), which I consider to be pretty good for a 500x500 bed. I'm not new to the 3D printing - my first machine was Reprap Mendel, then a few others, and now I have a Voron 2.4 as a main one. So it's fair to say I have a bit of experience. 🙂 However, I have no idea where this wavy pattern is coming from. I checked the bed with a straight edge and a feeler gauge - it is fairly flat but is dished in the middle. Not much of a dish though - under 0.05 mm in all directions except the 0,0 to 500,500 diagonal where it is under 0.1 mm. Now given the bed is flat, my thoughts are: I think the bow along the X axis is the result of X-beam deformation. This doesn't bother me for 2 reasons: 1. It is only 0.082 mm in magnitude. 2. This is a cold scan, so heat soaking will bow it the other way. The big dip in the corner is probably because the left gantry member is not coplanar to the right and is slanted down slightly towards the back. This can easily be fixed. The waves though! What causes those waves? They drive me crazy! Even though they are just around 0.02 mm in magnitude, I don't like them at all. Or, perhaps, I'm afraid because it is unknown to me, but isn't a big deal at all? What do you think?