Sadly no, it just resets the effect timer if that makes sense?

Like if two people bought SOFW & the effect was about to run out, it just resets if someone else applied it to you.

I think effects with a name (eg rapids) don't stack

Funny thing though sofw has literally the exact same stats as ardent. Which is crazy because the effect is a lot better on enchanters themselves and maybe most champs in league as well...I feel like they intended it to be *ardent with attackers, sofw with mages* but most of the time sofw is just better...