Immediately after switching the page, it will work with CSR.
Please reload your browser to see how it works.
And the study you are citing (8 to 12 year errors) - seems to report maximum errors, not averages. These might be caused by poor quality samples, so it's unfair to report it like that. Also the publication under discussion (epigenetic age oscillates) would answer where the fluctuations observed by the article you linked to come from - part of them are of course technical due to measurement error, but part of them are influenced by differences in sample collection times.
I also share your skepticism about intervention research and using "biological clocks" to measure how healthy you are. Curiously chronological clocks seem to not be easily affected by interventions. And I would guess this is why most people doing epigenetic aging for sport use biological clocks (like DunedinPACE). But then the question - if you are younger according to "biological age", but we still can measure your true chronological age accurately - are you actually younger in a meaningful sense.