How can I change Logos 9 to the beta channel?
https://community.logos.com/forums/t/52967.aspx - at the top of this forum - shows you how to do this and also highlights the risks.
Yes, make sure you read the warnings. Beta testing can be useful to FL, but it isn't for casual users, nor should you beta test on a "production machine." If you would be hurting if you lost access to Logos for a week or more, don't test on that machine.