Rollei Supergrain shelf life

I have a bottle of supergrain that's about 2 or 3 years old, never been opened. What are the chances it's still usable? Stored in a reasonably cool, vaguely dark basement.

Also curious what people's thoughts are on it. I am mostly a Rodinal guy, but keep meaning to branch out - used to use DD-X as well, nice stuff.

https://www.digitaltruth.com/products/rollei_msds/MSDS_Rollei_Supergrain,_english_version.pdf
pH~10.2, contains some phenidone, that might be the first to lose activity, but also dimezone-s which may still be OK.
Other ingredients I believe stable.
Not much known about sharpness in thiocyanate solvent at this pH.