Sorry to revive this old thread, but for future reference, USCIS updated its policy manual (here) which clarifies that someone who was absent between 6 months and 1 year and who was unable to overcome the presumption of interruption of continuous residence, has to wait 4 years and 6 months (or 2 year and 6 months if applying under the 3-year rule) after they return.
Interestingly, it also says that for someone who broke continuous residence by an absence of more than 1 year, in order for them to apply under the 4-year-and-1-day rule (or 2-year-and-1-day rule), they must present the evidence to overcome the presumption of interruption of continuous residence (like for absences of between 6 months and 1 year); if they are unable to do that, they must also wait until 4 years and 6 months (or 2 years and 6 months).
kinda odd requirement then, as in, no one would be able to use 2/4 year 1 day rule then.