When you asked "if the ribbon "slapping" is fatal"? I assumed you had a separate ribbon tweeter, (like a 3.6/3.7/20.7) which would be weird if that was slapping.
The 1.7i is a quasi ribbon panel, not a full separate driver, so no, Maggies will slap if over driven. You really should try to avoid that, but it's not fatal.
The 1.7i is a quasi ribbon panel, not a full separate driver, so no, Maggies will slap if over driven. You really should try to avoid that, but it's not fatal.