Feature idea: A “Semi UI” mode for older iPhones

I’ve been thinking about an idea for future versions of iOS.

Would it be possible for Apple to introduce a “Semi UI” or customizable system UI mode, especially for older iPhones?

For example, I’m using an iPhone 12. I really like the newer iOS design, but some of the newer visual effects can make older devices run warmer or use more resources.

Instead of having the entire system use either the old UI or the new UI, Apple could let users choose which parts of iOS use the new design.

For example, I could have the Lock Screen, Home Screen, Control Center, and Notifications use the new UI, while keeping Settings and the Keyboard on the classic UI.

There could also be options to reduce transparency, blur, and animations.

Basically, new UI where you want it and classic UI where you don’t need it.

It could even have three presets:

Classic: Maximum performance

Balanced: New UI with reduced effects

Full: Full new UI and visual effects

I think this would be a really nice way to let older iPhones enjoy the new design without necessarily putting as much workload on older hardware.

It would also be cool if Apple allowed us to choose this per system section, rather than having only one global Reduce Motion or Reduce Transparency setting.

What do you think? Would you use something like this on an older iPhone?