Here's my prepared query of the latest thing that I've tried. I call with the param bound naco_normalize of the URL.

select record
from metabib.real_full_rec
where tag = '856'
and subfield = 'u'
and index_vector @@ plainto_tsquery(?)

I have also tried building the query string by splitting the naco normalization of the URL and then joining with ' & '. I have not tried that with ' | ', because that would be too broad, I think. In the latter case, I tried both ? unadord and with to_tquery().