A certain hybrid auction can be accurately modelled as follows.
There are $n$ risk-neutral, rational participants $i=1,2,\ldots,n$, and a guy called Zerro: $i=0$.
Each, except Zerro, has a private value of the good (only known to themselves) $v_i\sim_\mathrm{i.i.d.} \mathrm{UNIF}(0,1)$.
An English auction (EA) is held. Zerro is allowed to, and does, open the bid at $0$. The participants then start bidding (or not). The EA results in a highest bid $B_\mathrm{EA}$ by $i_\mathrm{EA}$. However, no participant actually gets the auctioned good and no participant has to pay.
Then a Dutch auction (DA) is held. The starting price is $1$. All participants, including $i_\mathrm{EA}\ne 0$ (if he exists), can take part. (And all remember what happened during the EA.) If the price happens to reach $B_\mathrm{EA}$ then $i_\mathrm{EA}$ has won. The winner is denoted by $i_\mathrm{DA}$ and his price is denoted by $B_\mathrm{DA}$. The winner gets the good and has to pay.
This is a one-time affair. All participants come from different universes and will leave afterwards back to those universes.
All of the above, as well as this line, is common knowledge to the participants.
Question: What are the (possible) values of $B_\mathrm{EA}$ and $B_\mathrm{DA}$?
I'm hoping for either expectation values or specific values given $v_i, i=1,\ldots,n$.
This question is hopefully related to this question. That is my original question, but an answer to this, more theoretical, question could possibly add some background truth(s).