I managed to get POE running much better in crossover than the native Steam client. You should add
[DISPLAY]
renderer_type=DirectX12
to ~/Documents/My Games/Path of Exile/production_Config.ini, which solves the startup crash issue.
The solution is explained in detail in the following link: https://www.poewiki.net/wiki/Guide:Path_of_Exile_on_Mac_using_Windows_Client