I very much doubt that Arp ever worked with Setterfield.
And the articles don't really offer any hope for YEC. Slowing light is easy (refraction is the result of slowing light). But you can only get an apparent speed increase under very special conditions. So where is the evidence that those conditions applied to any significant fraction of the universe in anythign like the last 6000 years ?
Arp isn't mainstream. But at least he's got claims to be a scientific dissenter from he mainstream view (even if the evidence is against him) - Setterfield doesn't even have that - he's a YEC apologist.
As to the rest, I stated only that slowing light down is easy - not slowing light to a crawl. Not that that would help you. You need light to be speeded up by several orders of magnitude.
quote: There is no direct evidence that it ever happened. It is still very much alive only in the annals of theoretical physics
I am not sure that even Maguejiro's work is "still alive" as you put it. However it is no help for you since it postulates a relatively small increase far too long ago to help YEC views. And nothing closer to what you want could be considered "alive".
quote: I'm merely showing that it is possible to speed and slow light.
But those experiments do not show that either is possible under the conditions we observe. And they are in accord with mainstream theory which says that it is not possible to speed up light in the conditions we observe. So you really don't have a case here.