Carbon Copy Cloner rescue USB stick / add app to macOS USB installer?

[arw]

Hello,

having learned to appreciate the Acronis bootable USB sticks in the Windows world, I've been looking for something similar for the Mac.
I'd like to have a bootable "rescue" USB stick containing a compatible and working version of Carbon Copy Cloner to restore a CCC backup (dmg) to the internal drive. (license for CCC v5 and v6 available)
Basically macOS recovery mode but with CCC.

After creating a bootable installer via createinstallmedia is there a (not too complicated) way to add an application that can be accessed when booting from said pen drive? Similar to the additional tools that gets added when creating an installer for unsupported Macs?

Or can a working macOS installation be stripped so much of unnecessary stuff that it can be cloned and run from a USB pen drive?
I tried running a vanilla High Sierra install from a USB 3.0 Kingston DataTraveler Exodia M 64 GB and it took about 2 hours to boot to the desktop.
It works perfectly fine from a USB-HDD/SSD but the ~3$ for a pen drive are unbeatable.

I do not want to restore the dmg to the internal drive while being booted from it because:
- I noticed, not all files get actually restored from a backup when restoring to an actively booted drive
- I want a solution in case the internal drive is un-bootable or needs repairing

Any hints are appreciated. Thanks.

 

[Fishrrman]

You haven't told us what Mac you have, or what OS is running on it.
If it's an m-series Mac, I don't think this is possible any longer.

It -used to- be possible, but with the latest OS releases (and perhaps due to the hardware/firmware, also), it no longer seems possible to install a bootable copy of the OS onto a USB flashdrive (or even onto some platter-based hard drives).

I've tried late-version OS installs onto both flashdrives and platter-based hard drives, and they always failed (at least, for me).

This may be due to speed issues, or perhaps issues with the controller/firmware found in flash drives and HDDs.

But... there's a better way.

Get a cheap 2.5" SATA SSD. 128gb is all you need, can be found for $20.
Get a USB3 enclosure for it, like this:

SABRENT 2.5 Inch SATA to USB 3.0 Tool Free External Hard Drive Enclosure [Optimized for SSD, Support UASP SATA III] Black (EC-UASP)

SABRENT 2.5 Inch SATA to USB 3.0 Tool Free External Hard Drive Enclosure [Optimized for SSD, Support UASP SATA III] Black (EC-UASP)

www.amazon.com

Now, install a bootable copy of the OS to the SSD.
Put what utilities and apps you need onto it.

Now you have a bootable "emergency drive".

WARNING:
Again, not knowing what Mac you have...
Such emergency drive may -- or may NOT -- work with a [particular] m-series Mac.
They seem to be much "pickier" about what will boot them.

And... in order to use an external boot drive with an m-series Mac, the INTERNAL drive must still be "good" (i.e., functional). If the internal drive fails, you can't boot that Mac... AT ALL.

 

[arw]

Thanks @Fishrrman for exactly understanding my objective! I wanted to keep my question as general as possible but was not aware of possible conflicts.
I was only talking about Intel Macs up to Monterey where booting from a USB platter-HDD works perfectly fine for me.
Your suggestion (SSD + USB UASP enclosure) is exactly how I'm handling things now but I was looking for a cheaper solution. Not all of my Macs run the same version of macOS so I need multiple drives.

For now, I circumvented the issue:
- The only High Sierra device (Mac mini) got equiped with an HDD-clone in the 2nd empty bay
- All other devices are compatible with the same version of Carbon Copy Cloner and I can simply but them in Target#Disk-Mode

I‘d still be interested in learning how to modify a pen drive macOS installer to include additional tools - although Carbon Copy Cloner probably relies on more dependencies than there are available in the recovery environment hence the question might be irrelevant…