lulzbot mini print surface alternative options

What is a good alternative option to the PEI bed?

I only make mechanical parts, using materials such as Nylon 910.

PEI bed always gets uneven over time, and can be damaged by high heat.

Looking to change mini bed to something that just stays super flat! and doesnt require regular replacement due to becoming uneven

Thanks

The Lulzbotā€™s modular bed is a good option. PEI on one side and plain glass on the other side. Get spare borosilicate glass plates online as necessary.