While warping it could be that the printbed comes off the magnet and that's someting you don' want to happen. (See .gif video)
That's why I made these bed clamps you can print with a material that doesn't melt at the heated bed temperature. (I printed mine with PAHT-CF because I print a lot with that material)
Necessary materials:
Printsettings:
Please note that the STL of Part2 isn't orientated right.