APFS & HFS Partitions on MACBOOK PRO 2019 SSD 15-INCH

The 2019 MacBook Pros cannot run Sierra.

According to MacTracker, all 2019 MacBook Pros models originally shipped with macOS 10.14.5 (Mojave). That means they cannot run anything earlier. Mojave could run 32-bit applications, but I do not know if the particular ones you have in mind are compatible with it.

The 2017 MacBook Pros originally shipped with macOS 10.12.5 (Sierra). They cannot be updated to Sonoma or Sequoia – for them, Ventura is the end of the line.

Is there some reason why the older OS has to be Sierra instead of High Sierra or Mojave?

I would not suggest trying to run Sierra (which doesn't understand APFS) and Catalina (which would probably require you to use APFS) on the same drive. Separate drives, maybe; but you'll need to do it on a Mac that is compatible with both operating systems.

Apple's current instructions for installing two versions of macOS on the same physical volume assume that the drive will be using APFS, and consequently, that neither OS can be older than High Sierra.

Use more than one version of macOS on Mac - Apple Support

MacTracker is the best tool I know for quickly finding out which Macs can run both Sierra and Catalina. Apple's Support articles on identifying Macs only list the most recent version of macOS a particular model can run – not the earliest.

There's also the issue of whether you will be able to re-activate your Adobe software.

Adobe – Creative Suite archive (last updated: September 9, 2024)

"You can no longer reinstall Creative Suite 2, 3 or 4 even if you have the original installation disks. The aging activation servers for those apps had to be retired."

Unless your Boot drive is enormous, you would be far better served by using a small external drive, which can easily be made bootable for a different MacOS., But again, NOT older than the MacOS originally released with a particular Mac.

Yes you can do the partitioning you described if you must, but as others have already mentioned, not as far back as Sierra on the model Mac you mentioned.

A Mac cannot boot with an operating system older than what it originally came with. You may be able to run Catalina on a 2019 Mac. There is a slight chance you could even run Mojave.

The only way this computer will run Sierra is through a virtual machine software like Parallels.

None of these system support HFS boot partitions, so that part of your question is moot.

If you don't want to upgrade your Adobe products, consider replacing them with something like Pixelmator Pro or Affinity.

<< a 2017 iMac that came installed with Monterey. >>

no one told you this was based on what was Installed when YOU received it.

This is based on the very oldest MacOS that was EVER shipped on a Mac when first released, because that is the oldest version that has Drivers for its particular Hardware.

There are 2017 iMacs that SHIPPED initially with 10.12.4, Sierra.

lovely272 wrote:

This is not a question on operating system. A 2019 machine shipped with say Ventura can be wiped and rewritten with an earlier iOS.

It is a question of operating system. A 2019 MacBook Pro cannot boot macOS Sierra – and it cannot boot any version of iOS (the iPhone operating system) at all.

"If none of this works, what is the latest model year the configuration works?"

By now you should be getting a hint that none of us here think you can do what you want to do. Of course you are welcome try but no one here is going to bless your scheme as possible.

And all because you don’t want to update your now ancient and completely unsupported software, right?

Something else to consider.

Starting in April 2015, with the release of the 12" Retina MacBook, Apple used "butterfly key switch" mechanisms in many of their MacBook, MacBook Air, and MacBook Pro keyboards. They originally introduced this design because the 12" Retina MacBook chassis was so thin (allegedly too thin to accommodate a regular keyboard), but soon used it everywhere.

Unfortunately, if dirt gets trapped in keys with this design, it can be very hard to remove. Worst case being that you must replace the entire keyboard (and components glued to it) at a very high cost.

Apple had a keyboard service program to repair or replace "butterfly switch" keyboards that stopped working – but that program ended a while back, and they are no longer making those free repairs. Furthermore, some of the Macs that had the bad design are so old that you might not be able to get them repaired even if you offered to pay the bill.

The 16" 2019 MBP – which can't run Mojave – has a scissor-switch keyboard that Apple called a "Magic Keyboard." It marked the beginning of a switch away from the "butterfly switch" design – and none of today's Mac notebooks use a "butterfly switch" design.

But the ones that you're looking at? The ones that are as recent as possible, while still being able to run both Sierra and Catalina? I suspect you will find that they are all on the "butterfly keyboard" list.

iDropNews – FAQ | Which MacBooks Have the Butterfly Keyboard?