Q:

Should I use parenthesis in postfix `if` syntax? 

Are there any benefits to use parenthesis in postfix if statement?  like:
return 1 if ($self->found());

One of my workmate stick to use parenthesis and It's not common for me.   I would appreciate if someone point out differences. 
Following is output from perl -MO=Deparse
#! /usr/bin/perl
use strict;

my $found = 1;

print "FOUND\n" if $found;
print "FOUND\n" if ($found);

__END__
test.pl syntax OK
use strict;
my $found = 1;
print "FOUND\n" if $found;
print "FOUND\n" if $found;

A:

Parens are never needed around the condition in the if statement modifier, so consistency and playing-it-safe aren't factors. ( Same goes for the other statement modifiers.) 
I don't see any advantage to using them.  In fact, I find them a bit jarring. 
I believe most experienced Perl programmers don't use them, to the point that it's a fair indicator of "newbieness". 

A:

It's mainly a matter of style.   There's no requirement to use parens around the entire conditional expression and it has no effect on the way the code behaves, so decide for yourself what standard you want to use.   Personally, I don't, and my impression is that most Perl programmers don't either, but that could just be selection bias. 
I will note, though, that any time I start wanting to use parens within the conditional expression, that's a pretty good sign that it shouldn't be in a postfix clause, so then I put parens around the whole thing and change it to the if (...) {...} form.