Will it be an issue if I dirty flash android kernel? I am trying out a few kernels for my phone and I want to make sure that dirty flashing won't affect the efficiency of the kernel. If it does, what is the method to flash a new kernel without losing data and apps?
Use twrp to flash the kernels. Always keep a flashable zip of the stock kernel, in case you face any problem. I have seen requirements of many kernel developers that, you need to be on stock kernel before flashing the custom one. So, before flashing another custom kernel, it is always recommended to flash the stock one, then flash the custom one.