Treating newlines as whitespace between trigger functions arguments will enable multiline formatting.

Sure, it does not matter for short functions, but crowded functions involving several arguments, macros/macros overloads, being split to multiple lines, become more readable and easier to comprehend at first glance.

Consider a trigger expression example:

changecount(/Template ipset/ipset.entries[{#IPSETNAME}],{$IPSET_MISSING:"{#IPSETNAME}"},"all") = 0
and count(/Template ipset/ipset.entries[{#IPSETNAME}],#1:now-{$IPSET_MISSING:"{#IPSETNAME}"}) > 0

which could then be formatted as:

changecount(
    /Template ipset/ipset.entries[{#IPSETNAME}],
    {$IPSET_MISSING:"{#IPSETNAME}"},
    "all"
) = 0 and count(
    /Template ipset/ipset.entries[{#IPSETNAME}],
    #1:now-{$IPSET_MISSING:"{#IPSETNAME}"}
) > 0

Currently, when trying to split arguments with newline, frontend errors with:

"Invalid parameter "/1/expression": incorrect expression starting from ..."

Newlines in trigger expressions are not a problem by themselves. They are already being kept as-is when editing expressions, and automatically replaced by spaces in frontend tables.