Out of curiosity. 4051 is mentioned in 7777 and 8980 footnotes, even Byrnes' 8066 log. 4051 is my favorite scp, so I wanna ask about it. I'm not gonna bring up the 8980 Footnote since it's irrelevant to the following questions
7777: Can guess this myself, but if you wanna answer this (mystery purposes). Was there a specific reason 7777 brought up 4051's situation instead of directly saying Graham's crimes. Could just be wanting to mention him in the article, or maybe it was used so the Ethics Committee could "accidentally" uncover Graham's crimes.
8066: Did the research team in 8980 do experimention related things with 4051, or is it just there. Its got me thinking that if they didn't do work relating to 4051, why would Byrnes bring him up in his nightmare scenario
The consistent SCP-4051 references are mainly just homages to the original Site-17 Deepwell article (which is 4051). That said, to answer your questions:
7777: I've mentioned this once before, but originally there was no reason for this beyond it being funny. I later retconned this through 8980's implications on the combined setting, by making it so that the reason this crime was highlighted was because it was impossible to justify as serving the Foundation's mission, and therefore warranted a full investigation by the EC that the O5 approved.
8066: It's just a homage; they didn't do testing with SCP-8066 directly, Byrnes was just asked to do Steele's meaningless busywork because of SCP-8066's effects on his box of reality.