Custom G-code for color change does not process macro

[fe60]

Version

Version: 2.3.0+win64
Build: PrusaSlicer-2.3.0+win64-202101111315

Behavior

I want to increase the minimum distance between nozzle and heat bed when filament has to be changed during a print [1]. Therefor I have added a macro to the default G-code M600 (Printer Settings => Custom G-code => Color Change G-code).
M600 {if layer_height<70}Z70{endif}

For layers below 70mm I expect to see the following in the .gcode file.
M600 Z70 [2]

But instead of getting the Z-parameter, I see this in the .gcode file:
M600 {if layer_height<70}Z70{endif}

It seems the macro is not processed. Instead the content is transferred to the .gcode file as is.
The documentation about macros doesn't mention restrictions regarding the custom code sections the macros can be applied to [3].

Can you please get the macros working for the "Color Change G-code"?

Is this a new feature request?
No

[1] https://github.com/prusa3d/Prusa-Firmware/blob/MK3_3.9.3/Firmware/Marlin_main.cpp#L3169
[2] https://marlinfw.org/docs/gcode/M600.html
[3] https://help.prusa3d.com/en/article/macros_1775

[stringlapse]

Same issue here on the same version and build. I have {if layer_z < 30}G1 F300 Z30{endif} in my custom color change gcode and it's going directly to the gcode file without being processed.

[delaosa]

Same with version 2.3.0 in Linux, Pause g-code is also ignoring variables.

[mvadu]

Not only macros, it does not do even simple variable expansion. `M104 S[temperature] comes out as is in the final gcode file.

[bubnikv]

Implemented with 224f3e5

[SimonSolar2C]

This appears to be broken again in the Arachne version, 2.5.59