Since countability and 'masses' entered the discussion, my understanding
has changed slightly. Substances are uncountable. Non-substances are
countable. Unique is non-substance, so lo-Unique is countable (but when
you count it there is only one). So lo-Unique cakla might mean something
like "the one chocolate (of the sort that come in chocolate boxes)",
which in English might be said as "I like chocolates".
What has changed here is not my conception of lo-Unique but rather
my conception of what cakla means when not accompanied by a Substance
gadri.
(BTW, for Substance gadri, I am rather taken by xod's suggestion of
using not a special gadri or LAhE but an inner tu'o.)