Would it be far-fetched to apply the knockdown quality to Frag Grenades and Thermal Detonators?

Missile tubes too?

While I am thinking about it, give it to starship weapons used against character scale targets? I'm thinking of the battle of Geonosis and Obi Wan vs. Jango.

It wouldn't be far fetched I think... perhaps not from Frags, but Thermals and missiles sure... it makes narrative sense in some cases, others perhaps not.

I think dets and missiles "have" the knockdown quality already, in that 9 times out of 10 whoever gets hit with it isn't going to be alive/conscious enough to be standing anymore.