CC-reduplication

Regarding putative laryngeal-consonant reduplication in ἤγαγον (ḗgagon), I had encountered a mention of it in Roland Pooth's article on PIE verbal morphology, on pp. 22-28 where he discusses reduplication. However, it seems he was only discussing reduplication of *h₁s- (= *ʔ_s- in his notation), not *h₂C-. However, he describes *CeC- reduplication, which could apply to *h₂eǵ-. But not sure if the formation he describes would yield *e-h₂(e)ǵ-h₂(e)ǵ-om = ἤγαγον (ḗgagon) with the appropriate meaning.

The normal kind of reduplication only copies the first consonant. The consonant is s, the next consonant is also copied. This wouldn't give the Greek form, no, but I don't know what does.

Note that he also mentions *CeC- reduplication. That looks more like ἤγαγον (ḗgagon), but may not be quite identical in details of form or meaning. I'm going to see if I can find a description of the verb in Sihler, which I got ahold of finally.