Autos are more prone to compilations from transplanting. I have transplanted and few and have had some mixed results.
If you just starting out the best and easiest method to growing autos is by starting it off in its forever pot. No transplants and no HST.
You know you ran into an issue if it stops growing or enter flower earlier then expected.
As for the coir pots. they don't always breakdown fast enough and the roots may still become root bound then that's an issues all on its own.
best Of Luck!
***disclaimer, multiple people are answering all questions as there is a contest called GOTM, when a user is selected as the answer they get a point. Please see the contest page for information regarding the details:
growdiaries.com/giveaways/GotM-August-2022
Please note, when you reply to anything on the questions part of Growdiaries website, no one will be notified of this. Not even if you use a "@" tag in their name. Best to reach out to them in DM using your inbox, it can be found in the bottom right hand corner of the site. It's the small paper airplane button, it will be highlighted green if you have new messages***