There are guidelines for compiling iMX93 images without using Yocto, such as flash.bin and Linux kernel?
Yes, you can, you can compile u-boot and linux in the Standalone way.
https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/Detailed-Operations-For-Standalone-On-Li...
https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/I-MX%E5%A4%84%E7%90%86%E5%99%A8%E5%9C%A8...
Hope this can do help for you
I have read the documentation you provided, which only covers the compilation of u-boot and Linux kernel. Is there anything about how to create flash.bin without using Yocto?