Boldenone interacts with aromatase itself and produces an estrogenic metabolite that artificially inflates ECLIA blood test results.
It may or may not convert into Estrone, the guess is that it doesn't convert to anything bioidentical, but does convert to a synthetic estrogen that has its own unique affinity for ERα and ERβ.
Now the question really becomes what is that synthetic Estrogen, and how potent is it at fulfilling the same physiological functions as Estradiol.
This is the question we commonly arrive at with Dianabol or Trestolone (MENT), but for some reason with Boldenone it is overlooked entirely.
At least we know what to expect from the methylestradiol via Dbol and the 7α-methylestradiol via MENT.
With Boldenone we have no idea what's going on, but anecdotally its estrogenic activity seems lackluster, and the fact that it essentially completely inhibits the aromatization of Testosterone > Estradiol makes it a very difficult compound to leverage effectively and safely.
Research also suggests that Boldenone is one of the most nephrotoxic compounds in existence.
The competition for aromatase, the subsequent inhibition of downstream cascades affecting important physiological functions, the huge spike in blood viscosity, and the potential kidney toxicity all make this a compound that is hard to find a place for in performance enhancing drug stacks.