May I suggest trying the kernel boot option "acpi_osi=" in the place of the option you suggested?

This will correct a lot of issues with sleep and hibernate.

But to answer your question as you asked.

It is recommended to test the parameter on this setup before adding it, one would suggest you hold the space bar when powering up the system to catch the boot menu, then hit the "e" key to edit the line command line and test your boot option before saving it.

kernelstub works as following

To add a boot use -a "options" yours would be as follows

kernelstub -a "mem_sleep_default=deep" 

To delete a boot option use -d "options" yours would be as follows

kernelstub -d "mem_sleep_default=deep"

and

# kernelstub -p
kernelstub.Config    : INFO     Looking for configuration...
kernelstub           : INFO     System information: 

    OS:..................Pop!_OS 22.04
    Root partition:....../dev/dm-1
    Root FS UUID:........f3b6a3b7-32e7-4f9c-9b8d-1952d5d8e0f3
    ESP Path:............/boot/efi
    ESP Partition:......./dev/nvme0n1p1
    ESP Partition #:.....1
    NVRAM entry #:.......-1
    Boot Variable #:.....0000
    Kernel Boot Options:.quiet systemd.show_status=false splash loglevel=0 acpi_osi=
    Kernel Image Path:.../boot/vmlinuz-6.2.6-76060206-generic
    Initrd Image Path:.../boot/initrd.img-6.2.6-76060206-generic
    Force-overwrite:.....False

kernelstub           : INFO     Configuration details: 

   ESP Location:................../boot/efi
   Management Mode:...............True
   Install Loader configuration:..True
   Configuration version:.........3