I think generally, though, the idea is sound. (Tangent: I hate sports stats that are inexorably tied to betting; I'm not interested in the ROI on these games, just whether there's an advantage).
Yeah...all the gambling crap makes that hard to follow (what the heck is "units won," and what does "ROI" mean in this context? I don't know and don't care). So I did the research myself.
Here are the 2000-2020 road records of the Chargers, Raiders, 49ers, Seahawks (and, from 2016-20, the Rams) against teams in the eastern time zone:
Rams..............................11-5 (.688)
Seahawks........................34-30 (.531)
Chargers.........................30-40 (.429)
49ers..............................21-35 (.375)
Raiders...........................20-47 (.299)
TOTAL..........................116-157 (.425)It is, I think, interesting to see that, over 21 seasons, the Chargers played 25% more road games against eastern time zone teams than the 49ers.
NOTE: I did not take into consideration games played in London.
I guess the moral of the story is that the Rams have been remarkably good in eastern time zone road games, and the Raiders have been consistently bad (only four times during the 21 seasons did the Raiders have a winning record in these games).