I'd write

while( my $rows= 0 + $dbh->do(...) ) {
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in this case.

I'd prefer "00" but it looks less like a real number to some people than "0E0". Therefore, "0.0" might be an even better choice.

I like the feature. It makes it easy to pick whether you want to care about number of rows or about success (simply add "0+" or "0==" or don't).

When RaiseError is turned on, it isn't useful. So I could see adding an option for PlainZero which would default to "never" (for compatability) but could be changed to "always" or "only when RaiseError is off". Though I probably wouldn't use such a feature since I see too much risk from action-at-a-distance with it.