Mbed version for a specific project

Hi, for an existing project, I need PlatformIO (under VS Code) to use a specific older version of mbed 5.
Can you please guide me on how to configure / change PlatformIO to acheive this?

Additionaly, how to add / remove features on this same project?
It seems that settings in the mbed_app.json are ignored.

What is your hardware?

Hi Ivan,

The hardware is proprietary. PlatformIo seems very promising, and we were about to purchase a license.
We decide not to go this way, because of the highly dependence on the development platform.
No professional work can depend on IDE / Platforms. We need to make sure that in 10 years,
we can modify, compile, and rebuild any firmware. This is not the way PlatformIo works because of automated updates.
Also, we need that all firmware dependency is within the project tree, not somewhere else in the
development computer. Having a system that makes updates without my confirmation is not suitable at all.
If you were able to explain how this can be achieved, I may rethink my decision of not using this platform.

On the which MCU it is based?

This is not the way PlatformIo works because of automated updates.

By default, you use the latest version of dev/platform in platformio.ini. See Redirecting...

Also, the release notes have all details about internal frameworks and their versions. For example, ST STM32 => Releases · platformio/platform-ststm32 · GitHub