Snapped main stem of young plant. Taped it and supported with stick - Is it worth saving or should i plant something new?

I would leave it alone for now and see how it does. If you used duck tape how you plan to get it off? Plus the stem can't breath. So you might likely end up throwing it all out in the long run.

hemp is resiliant- thats the good news she should be fine in 2-3 days and continue to grow, stronger than before

screwed either way... you start something new it'll be just as far behind the others - at least this one should ripen in same time frame -- this may or may not be important to you. What you ultimately doe depends on your specific context, wants and needs. e.g. if you were tight for space, this could be helfpful. while not always an option for expensive seed, it's a good practice to plant 125-150% of what you need. kill the weak ones. When yo plant a greater number, this becomes more important. Last year i sowed 12, and i ended up with 2 runts and a herm. Shit happens. This was bad luck, but while not common is still within the 'norm.' this is one of the reasons i stopped buying expensive seed. One, it wasn't worth it, lol, and two, you cannot jsutify throwing out 20/seed. I just planted 150% of what i need moments ago. the excess 50% were my home-brew seeds. I won't feel bad about throwing those out. Those are less than a 1/3rd of a penny in cost. Shows what kind of margine these guys run - even the ones that keep it to 10 $ or less per seed. there are usually loads of free seeds to be had... keep those for your excess and don't feel bad about throwing some out that aren't defective. Sexual reproduction is complicated. 60% of inseminated ova in humans fail before birth. If you don't want to be scared shitless, don't look up how many defects happen to the ones that do survive. FFS, 1/10,000 is born with a tail! The tail is not the funny part... the false perceptions of reproduction among the general population is the funny part.

Since it's auto I'd definitely scrap that plant and go with something new instead - she won't have time to recover and will not yield anything good. On the other hand If that was photoperiodic plant then you could just give her a few more weeks in veg, in the case of an auto - there's no such luxury.