iFixit, from the comparison teardowns of the iPhone SE and iPhone 8:

iPhone SE’s cameras, SIM tray, Taptic Engine, and display assembly (including the microphone and proximity sensor) are all swappable with iPhone 8 parts.

And:

That screen should be cheaper to replace than any new iPhone we’ve seen in years. However, as with any modern iPhone screen swap, you will lose True Tone unless you have access to a screen programmer.

And:

Home buttons are still not interchangeable—you’ll need to hold on to your original home button in the event of a repair, substitute an aftermarket home button with no Touch ID, or else pay Apple whatever they ask to fix it for you.

And:

Although the battery looks identical, the battery’s logic board connector differs from the one in the 8, so they don’t fit together. The SE will connect to an iPhone 11 battery, which uses the same connector—but it won’t turn on. And, sadly, this seemingly throwback phone has some very modern Apple roadblocks inside. You can’t even swap one genuine iPhone SE 2020 battery for another without triggering a “not a genuine Apple battery” service warning.

Barriers to self-repair. But at the same time, keyed parts to keep repairs from going wrong. Interesting article.