I've tried using the fix in https://tex.stackexchange.com/a/492197/193767 in order to make TikX's remember picture feature usable, Code below, just in case:

\unprotect
% This fixes the present bug
\unexpanded\def\pdflastxpos{\numexpr\clf_lastxpos\relax}
\unexpanded\def\pdflastypos{\numexpr\clf_lastypos\relax}
% This might be needed if you run PGF 3.1.3
% see https://github.com/pgf-tikz/pgf/issues/675
\def\XC@tgt@mod#1{#1}
\def\XC@sdef#1#2{\edef#1{#2}}
\protect
\usemodule[tikz]
\starttext
\starttikzpicture[remember picture]
     \node (A) {Node 1};
\stoptikzpicture
Hi world
\starttikzpicture[remember picture]
    \node (B) {Node 2};
\stoptikzpicture
\starttikzpicture[overlay,remember picture]
    \draw (B) --++(0,0.5) -| (A);
\stoptikzpicture
\stoptext