Not quite, if a ‘truth’ is defined as some ‘justice’ then there could be an unprovable ‘justice’ that should be carried out, we just can’t reason our way there.
(again disagreements like this are usually because of a disagreement of terms)
Sure, my claim is exactly that there are infinitely more propositions that are not about justice. My claim is that justice concerns a finite set of propositions that can be enumerated (as in, murdering someone involves propositions related to justice, making decision about whether to take a deep breath right now does not involve propositions related to justice).
(again disagreements like this are usually because of a disagreement of terms)