Tense blindness?

Continuing his critique of Ed Feser's defence of presentism,  Here Bill writes,

Bivalence, as a principle of logic, strikes me as pretty solid.  But now consider: could the applicability of a principle of logic depend on when it is applied?  Could the passage of time restrict its application? Take identity: for any x, x = x.  Everything is self-identical. If this is true for temporally present values of 'x,' I should think it would be true also for past values of 'x.'  I am self-identical, but so is Alfonso, who is wholly past. When he ceased to exist, he didn't cease to be self-identical. When I refer to him now, I refer to the same man I referred to when I referred to him when he was alive. And when I cease to exist,  I won't cease to be self-identical.  I won't become self-diverse, or neither self-identical nor self-diverse.  The mere passage of time cannot bring it about that a principle of logic that applies to a thing in the present ceases to apply to that thing when it become past.

I think Bill is expressing the thought that while he exists we truly say, Bill is self-identical, and that after he has ceased to exist we will truly say, Bill was self-identical.  The change of temporal vantage point does not alter Bill's properties.  It changes the tense in which their possession is expressed.  But look at the wording of the underlined sentences.  Bill seems to be saying that after a thing ceases to be it will remain self-identical.  On the face of it this is inconsistent with Bill's assertion here that nothing can have properties unless it exists, assuming self-identity is a property.

Further,

We are being told that wholly past items exist in that their effects in the present exist.  Here is an example, mine, not Feser's. Tom stood outside of Sally's window a few days ago.  That event on presentism does not exist. It is not just that it does not exist now -- which is trivially true -- it does not exist period. For on presentism, only what exists now exists period or simpliciter.  And yet  Tom's standing outside of Sally's window is not nothing: it actually occurred.

Well, Tom's standing wasn't nothing while it was ongoing.  But it is now, and has been ever since Tom ceased his loitering.  I fully appreciate the eternalist's sense of the 'thereness' and fixedness of the past.  But why does he want to speak of it in the present tense?  What's wrong with the past tense?