Is there a better way to see if a bit vector has all its bits set to '0'?

Yes. Combine the checksumming (%nn) and bit (b*) formats of unpack:

## 800 zero bits
$bitVec = chr(0) x 100;;
print unpack '%32b*', $bitVec;;
0

## Set 1 bit in the middle
substr $bitVec, 50, 1, chr(1);;
print unpack '%32b*', $bitVec;;
1

## set 8 bits in the middle
[0] Perl> substr $bitVec, 50, 1, chr(255);;
[0] Perl> print unpack '%32b*', $bitVec;;
8
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