The manual LMTX-primitives on page 21 tells me: You can explicitly freeze an unfrozen macro.
...
A redefinition will now give: You can't redefine a frozen macro.
But is this true? The following code seems to contradict this:
\def\HOME{myhome}
\writestatus{1}{\meaning\HOME}
\letfrozen\HOME
\writestatus{2}{\meaning\HOME}
\def\HOME{other home}
\writestatus{3}{\meaning\HOME}
Is this mechanism broken? It looks so useful to prevent accidental redefinition!
dr. Hans van der Meer