Asus RT-AX53U overlay size

Hi, I recently bought Asus RT-AX53U as replacement for Archer C6 ( mainly because flash size ) but after installing 23.05.03 build of openwrt overlay partition is only ~33MB.

AFAIK this router supports dual firmware, but I don't need it and I would appreciate all the available NAND storage ( should be around 100MB ), can I do something about it w/o forking and building firmware myself?

You could wipe the 2nd firmware and add it as an extroot, but it wouldn't be the same partition as the default /overlay.

You can use USB stick without breaking revert to OEM