Unified Debugger Standalone use

I’m using PlatformIO with VisualCode (all up-to-date) on Win10.
I would like to use the Unified Debugger in Standalone mode, that means no building before debugging.
In my project there is very sophisticated (complicated) build system and I need to provide the debugger with already build ELF file. (Something similar to Cortex-Debug extension of VS Code).
I went through the documentation and I see that this is not an intended use case of PlatformIO.
Nevertheless, is there a possible workaround how to provide the debugger with ELF file and start the debugging session directly?

Can you prepare this firmware with PlatformIO?

No, nor do I want to. I would like to stick with CMake/Make and use only the debugger from PlatformIO.
But of course, everytime I start the debugging session, PlatformIO triggers Build action, which is not configured and fails, thus aborts the debug session.

What is your MCU? Did you try Cortex-Debug?

Hello, MCU is STM32F417ZG.
Cortex-Debug works, but it does not offer enough debugging features, like memory debug, or watchpoints.
That’s why I’m trying to make Unified debugger work, because it offers powerful debugging features.