No 0.5mm isn't terrible at all until you think of it this way where that would makes up for a three-layer height difference in a print and I know that not how it would print but it the the unevenness in the first layer would cause issues later on in muilt part prints. I was thinking the Z Gantry could have played a little bit into the bed mesh looking like this but it looks like it's the bed itself do the cuz I rotated it and the warp followed