Warped bed :( seems like a common QC issue

Today I received a new V3 bed from Bambu. Same Banana garbage, 0.4 mm cave in X direction, mostly flat in Y direction except area near to calibration board. However I expect it to be much worse when hot but did not try running its heater yet. So I was right to not wait for Bambu and modding original bed with FullMetal™ plate. Printed a few things yesterday evening and today and results were simply godlike compared with printing on banana garbage.