I think you're overthinking this a bit.. In my view you have a few options:
- Wear the watch at least once every couple days. It'll keep time & date and you'll only have to advance the time / date 1 hour or day for daylight savings time (twice a year) or date to account for 30 vs 31 days (so date change once every 2 months).
- Put the watch in a winder. Similar to above, you'll only have to change 1 hour / 1 day at most.
- Just adjust the time however you like. The movement is robust enough that it will not break being set backwards, but YMMV as these are reps at the end of the day.
All that said, I hope you got the watch from the real CTime (linked from this forum) and not a CTime imposter. In any case, they may be telling you not to set backwards just in the abundance of caution.
... and now I am guilty of 'overthinking' this