An architect makes the design decision to install ESXi on embedded and resilient 8 GB...

https://kb.vmware.com/s/article/2074026 You can store coredumps on the SD boot media, but refrain from configuring the scratch partition here as the logs are write intensive and can cause the SD card to fail faster resulting in re-installation of ESXi

https://blogs.vmware.com/vsphere/2021/09/esxi-7-boot-media-consideration-vmware-technical-guidance.html

A configuration involving the usage of SD card or USB drives as boot media is a minimum of 8 GB SD card or USB drive + Locally attached persistent storage device for ESX-OSData partition may be used but is also not recommended. Recommended list of locally attached storage devices are listed below.In any case, if an SD or USB device is used for boot media (only SD/USB or SD/USB + local HDD/SSD disk), follow the below instructions to reduce the amount of IO sent to the SD or USB boot media:Enable the ToolsRamDisk option to offload VMTools install/upgrade IO requests on the RAM disk.Ensure the /scratch partition is configured on persistent storage like a local HDD/SSD or boot from the SAN device.