Bless error when installing rEFInd
If you wish to attempt to use rEFInd from a MS-DOS partition, then follow the instructions below. I have made the following assumptions.

You will be reusing disk0s3.
System Integrity Protection is enabled.
You have booted to macOS. Do not boot to macOS Recovery.
Secure Boot is is set to &quot;No Security&quot;.

Below are the steps.

Enter the following command to change disk0s3 to a FAT formatted partition.
sudo diskutil eraseVolume MS-DOS BOOTMGR disk0s3

You could also change the partition by using the Disk Utility application. Highlight the partition then select Erase. Use BOOTMGR for the name and MS-DOS (FAT) for the format.

I assume you have downloaded the current version of rEFInd (refind-bin-0.11.3) to your Downloads folder. Enter the following command to change to the root directory of the rEFInd download.
cd ~/Downloads/refind-bin-0.11.3


Enter the following command to install rEFInd. I omitted --alldrivers since both macOS and Kali Linux do not needed any rEFInd supplied drivers to boot on a Mac. Also, adding --alldrivers caused rEFInd to hang on my 2011 iMac.
sudo ./refind-install --root /volumes/BOOTMGR

You should get the following alert followed by some additional error messages.
**** ALERT: SIP ENABLED! ****

You can ignore this alert. At the prompt shown below, enter y.
Do you want to attempt installation (Y/N)? 

The follow error message was expected and can be ignored.
Could not set boot device property: 0xe00002bc


Rename the refind folder to BOOT and the refind_x64.efi file to bootx64.efi so that the Startup Manager will include it as a startup option. This can be done with the Finder application or by entering the commands given below.
cd /Volumes/BOOTMGR/EFI
mv refind BOOT
mv BOOT/refind_x64.efi BOOT/bootx64.efi


Add a label for this new startup option. Without a label the Startup Manager will show EFI Boot which may be confusing if you have other partitions with an /EFI/BOOT/bootx64.efi file.
cd /Volumes/BOOTMGR/EFI
bless --folder BOOT --label rEFInd


(Optional) Goto my Mac icons website and download the mac-icons.dmg file. Use the Finder application to mount this file. Enter the command given below to copy the rEFInd icon to BOOTMGR volume.
cp /Volumes/mac-icns/OSX10.11.6/os_refind.icns /Volumes/BOOTMGR/.VolumeIcon.icns

The icon shown below will now appear in the Startup Manager above the rEFInd label.


Restart the Mac and immediately hold down the option key until the Startup Manager icons appear. Next, select the icon labeled rEFInd. Finally, hold down the control key and select the circular arrow below the rEFInd label. This effectively blesses rEFInd.


Changing which drivers are used
The drivers used to access file systems by rEFInd are stored in the /Volumes/BOOTMGR/EFI/BOOT/drivers_x64 folder. You can create a new folder named drivers_x64_not_used in the /Volumes/BOOTMGR/EFI/BOOT folder. You can then move any drivers you do not wish to be used by rEFInd from the /Volumes/BOOTMGR/EFI/BOOT/drivers_x64 folder to the /Volumes/BOOTMGR/EFI/BOOT/drivers_x64_not_used folder.
If you are still getting a grey screen or a no entry sign, this link shows that you will have to copy the apfs driver in order to boot. To do so, run the following command.
cp /usr/standalone/i386/apfs.efi /Volumes/BOOTMGR/EFI/BOOT/drivers_x64.

You may still have one boot option that shows the 'no entry' sign but the other option should now boot you into macOS instead of showing you a grey screen.