Electrolytic capacitors as Mains transient protectio

Hi,
Page 12 (RHS) of this PFC module datasheet talks of using the PFC output electrolytic capacitor bank for
mains transient handling...

Indeed, it is well and widely known that you post bridge electrolytics are your best protection
against mains transients.

Admittedly it is a surprise since a mains transient is considered to be just 50us long as in the following at
5th page (page 3) of this....

So, many of these transients, I would have thought , will not even make it through the AC line filter. -The Diff mode
L and C there would quench many transients, down to a mere "voltage blip".

MOVs as we know, are pretty awful, since they die and crowbar the mains fuse after a couple of transients.

What is needed now, is surely to connect a big electrolytic capacitor to mains Line and Neutral via a full wave bridge...and add a discharge resistor.
Surely this is the new breed of mains transient protection module? Cheaper and doesn't die on you like a MOV does.