If we have a simple sao, then there is no confusion in omitting punctuation before the {'e'}.

But if we have an adverb, or a time stamp before the {'e'}, then wouldn't it be clearer if we added some punctuation before that adverb or time stamp ?

for example:

wagh vIghro'mey tIQ 'e' wISov 

we know that ancient cats are expensive 

wagh vIghro'mey tIQ reH 'e' wISov 

we always know that ancient cats are expensive 

Isn't it better to have some punctuation before the {reH} ? And if yes, which punctuation ?

I don't see that it's better.

If I had to use punctuation, I'd use a comma. It's the least separating of all of them, and is often interpreted as merely a pause.

-- 
SuStel
http://trimboli.name