I have (and use) a micrometer carriage stop. It has nothing whatever to do
with stopping the machine's turning movement in the X axis. Rather, I use
it for setting up shoulders. Face a part, mount a cutoff tool, bring the
edge of the cutoff tool to rest against the work, zero the carriage stop and
bring it to rest against the carriage, then crank out the carriage stop the
desired amount and move the carriage (by hand) until it again rests against
the stop, then lock the carriage and use the cutoff tool to machine the
shoulder.

I don't think a carriage stop of this nature should EVER be used to try to
stop the carriage in any kind of safety sense.

There are such carriage stops, but not on my lathe. Typically they kick the
carriage feed out of gear. I have heard of lathes without this feature being
outfitted with electrical limit switches which will kill the power to the
machine. This has somewhat the same effect, except it seems likely that the
power train's rotational momentum would keep the carriage feeding for some
time before frictional forces (and cutting forces should the cutter be
engaged) stopped it.

The 2 kinds of carriage stops I write about are VERY DIFFERENT and they
should REALLY not be confused.

I hope that's clear enough.

GWE