Moving from iMac to MBP - time machine, migration, downgrading

[YYY]

So I got a refurbished A+ MBP 13.3" 2017. it came with Catalina installed which I don't want. I made a time machine backup of the El Capitan iMac and was hoping to simply restore the iMac to the MBP. Cannot do. Time machine will only restore to the same Mac model. I have no CCC of the iMac and it is already erased and not with me. What do I do now? I just want the el capitan imac to run exactly as it was but on the MBP.
I thought about :

1. get from a friend (I have limited data plan at it's end at the moment) a 6GB el capitan installer on a USB stick
2. Create a bootable el capitan drive on my formatted iPod - do it with createinstallmedia command in terminal?
3. restart the MBP catalina on a recovery mode
4. Erase it - should I format it as NTFS?
5. restart it in recovery mode with the bootable el capitan on iPod connected
6. Install el capitan on the MBP
7. use migration assitant to move my data from the iMac el capitan time machine backup - applications, files, settings, everything - to the fresh MBP el capitan

Is this going to work?
Any issues that are likely to pop up?
Will my data and apps run as they did on the iMac?
Do I need different user names on the MBP el capitan install than the user of the iMac el capitan?

any one had done that before and got any tips?

Thank you!

 

[Raz0rEdge]

What are the reasons you don't want to be on Catalina? That MBP likely came with High Sierra, so you couldn't install El Capitan on it anyway.

Downgrading the OS should be your absolute last thing since most apps require Sierra/High Sierra to operate. The ONLY way this makes sense if you are going to downgrade ALL of your applications to what used to work with the older version of macOS and NEVER upgrade them, (ship in a bottle style).

 

[YYY]

What are the reasons you don't want to be on Catalina? That MBP likely came with High Sierra, so you couldn't install El Capitan on it anyway.

All my adobe apps are 32 bit. none will work with catalina. cannot afford to buy and install all apps.

Why cannot install el capitan on a 2017 MBP running catalina?

 

[YYY]

Downgrading the OS should be your absolute last thing since most apps require Sierra/High Sierra to operate. The ONLY way this makes sense if you are going to downgrade ALL of your applications

None of my apps from the iMac require anything higher than el capitan. they all worked just fine.
Why would I need to downgrade any apps that run on an el capitan ... in order to run them on el capitan installed on the 2017 MBP?
Thnak you

 

[badshoehabit]

What are the reasons you don't want to be on Catalina? That MBP likely came with High Sierra, so you couldn't install El Capitan on it anyway.

Because you can't operate a machine on an OS which predates its inception.

Use the Mac operating system that came with your Mac, or a compatible newer version – Apple Support

 

[Raz0rEdge]

The way Macs work you can only downgrade (re-install) the OS that it came with. El Capitan was released on 2015, Sierra in 2016 and High Sierra in 2017. So a 2017-vintage Mac came with either Sierra or High Sierra and will not allow anything prior to be installed, that's just the way it is.

If 32-bit apps are your limitation, a valid one it is, then you show downgrade to Mojave and stay with that for a while.

That way, you can continue using your 32-bit apps and you are on a supported version of macOS for your other applications for some time to come. You shouldn't drop down 3+ releases because while the 32-bit apps will work, other apps, like your Browser or something else might not be happy.

 

[IWT]

Why cannot install el capitan on a 2017 MBP running catalina?

A good question and the answer is not intuitive. Fact is that a Mac will not run any Operating System (OS) earlier than the one with which it shipped when brand new.

Ian

- - - Updated - - -

You're a fast typist, Ashwin; but at least we said the same thing

PS And Sue!

Ian

 

[YYY]

that is sad news for me? what are my options? will time machine backup move my stuff using migration assitant to catalina and then none of my sw will work?

 

[usagora]

that is sad news for me? what are my options? will time machine backup move my stuff using migration assitant to catalina and then none of my sw will work?

As Ashwin suggested, you can install Mojave (10.14) on your 2017 MBP and all your 32-bit apps will still run.