For example in the case of Mounted filesystems discovery, it would be useful to be able to dynamically create user macro and relevant user macros with context.

Example:
LLD discoveres filesystems /, /opt, /tmp

User may define {$VFS.FS.PUSED.CRIT} macro within the LLD rule with some arbitrary value as a threshold, say 90%.

User may also define {$VFS.FS.PUSED.CRIT:"

{#FSNAME}

"} macro with some arbitrary value as a threshold, say 95% just to denote the difference.

 

As a result, template will be populated with the following macros coming from the LLD rule:
{$VFS.FS.PUSED.CRIT} -> 90%
{$VFS.FS.PUSED.CRIT:"/"} -> 95%

{$VFS.FS.PUSED.CRIT:"/opt"} -> 95%

{$VFS.FS.PUSED.CRIT:"/tmp"} -> 95%

This will make it easier for users to control individual thresholds without the need to define the macros manually.