The Library is just really unusual content. There aren't really any demos or how tos. They are more like hour long physical dialogues with great legends of the sport. But, some sessions do have specific bagwork sections where a lot can be learned. Legends teach how they did bagwork, and how they trained techniques on the bags. Here is a list of sessions with bagwork in them, but you would have to watch the whole session. Colored sessions are some of the best overall sessions.
Arjan Surat 1 - Old School Master
Metprik Silachai - Old School Muay Maat Lowkick Pressure
Yodwicha Por Boonsit 3 - Spearing the Middle, Fighting With Rhythm
Wangchannoi Palangchai 1 - Deadly Step Counter Fighting
Arjan Surat 2 - His Old School Tough & Defensive Style
Langsuan Panyutapum - Monster Muay Khao Training
Samson Isaan 1 - The Art of Dern Fighting
Dieselnoi Chor Thanasukarn 2 - Muay Khao Craft
Boraphet Pinsinchai 1 - Muay Khao Mastery
Yodwicha Por Boonsit 2 - Clinch Techniques & Defense
Dieselnoi Chor Thanasukarn 1 - The King of Knees
Wangchannoi Sor Palangchai 3 - Advancing Counterfighting
Matee Jedeepitak - The Keys To Femeu Timing & Distance
Kaisuwit "Kru Pern" - Muay Maat Centrifugal Power
Eagle Den Junlaphan 2 - Boxing Within Muay Thai
Arjan Yai Muangsupan - Golden Age Forms & Dynamics
Jampatong Na Nonthachai - The Master of the Head Kick
Pudpadnoi Worawut - The Basics from the Legend
Phetdam Sor Suradet - Style, Rhythm, and Timing
Gulapkao Na Nonthachai - Old School Forms & Rhythms
Tepniramit Sitsamnao | Defend and Punish
Pairojnoi Sor. Siamchai - Balance, Footwork & Intensity
Chanchai Sor. Tummarungsri - The King of Teeps
Kru Ali Phet Kalim - Old School Forgotten Principles
Manop Manop Gym 1 - The Art of the Teep
Krongsak Prakong-Boranrat - That Shoving Energy
Silapathai Jockygym - Master of Teep Distance
Hippy Singmanee 1 - Developing Power
Thanks for all the kind words and support. As a beginner it may take a bit of effort to get into it, but because you are connecting to the pure thing, the real thing, the benefits will really be amazing.